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Extensiveness and perceptions of lecture demonstrations in the high school chemistry classroom

ProQuest Dissertations and Theses, 2011
Dissertation
Author: Daniel S Price
Abstract:
While lecture demonstrations have been conducted in chemistry classrooms for hundreds of years, little research exists to document the frequency with which such demonstrations are employed or their effect on learners' motivation and performance. A mixed-methods research study was performed, using quantitative and qualitative survey data, along with qualitative data from follow-up interviews and structured correspondence, to determine the extent to which lecture demonstrations are used in high school chemistry instruction, and the perceived effects of viewing such demonstrations on students' performance on course assignments and on motivation to excel in current and future chemistry courses. Fifty-two randomly selected chemistry teachers completed a survey regarding their present and projected use of classroom demonstration. Twelve of the survey participants provided elaboration in the form of an extended questionnaire. Data indicate that all except one of the survey participants currently employ lecture demonstrations, and all anticipate performing the same amount of, or more, demonstrations in their future instruction. Extended questionnaire and survey data reveal that the participating chemistry teachers perceive substantial positive effects on students' performance on classroom assignments and a lesser, though still positive, effect, on learners' motivation. No correlations were observed between the number of lecture demonstrations performed and educators' years of experience teaching chemistry, previous exposure to demonstrations, or undergraduate degrees earned.

Table of Contents

Abstract

................................ ................................ ................................ ..........................

ii

Copyright

................................ ................................ ................................ ......................

iii

Dedications ................................ ................................ ................................ .....................

iv

Chapter One:

Introduction

................................ ................................ ...........................

1

Context of the Study

................................ ................................ ........

1

Definition of Lecture Demonstration

................................ ................

1

Purpose of the Study

................................ ................................ ........

3

Primary Research Questions

................................ ............................

4

Minor Research Question

................................ ................................ .

5

Significance of the Study

................................ ................................ .

5

Chapter Two:

Review of Literature

................................ ................................ ..............

7

Introduction

................................ ................................ .....................

7

Justifications for use of demonstrations

................................ ............

7

Increased student motivation

................................ ............................

9

Increased student learning

................................ ..............................

11

Substitutes for laboratory experiences

................................ ............

1 4

Summary of, and defici encies in, literature

................................ ....

1 4

Chapter Three:

Methodology

................................ ................................ .......................

1 6

Introduction

................................ ................................ ...................

1 6

Population and sample

................................ ................................ ...

1 6

Variables and measures

................................ ................................ ..

18

vi

Limitations

................................ ................................ ....................

19

Procedural steps

................................ ................................ .............

20

Survey instrument

................................ ................................ ..........

2 1

Ethical considerations and sampling method

................................ ..

22

Methods for data analysis ................................ ...............................

26

Validation and reliability

................................ ...............................

30

Pilot study

................................ ................................ ......................

34

Chapter Four:

Results

................................ ................................ ................................ .

3 6

Introduction

................................ ................................ ...................

3 6

Survey sample

................................ ................................ ...............

36

Survey results

................................ ................................ ................

37

Commentary and

context

................................ ...............................

4 2

Teachers‘ purposes and perspectives

................................ ..............

4 4

Research questions ................................ ................................ .........

5 3

Chapter Five:

Discussion

................................ ................................ ...........................

5 7

Prevalence of demonstrations

................................ .........................

5 7

Perceived effects

................................ ................................ ............

5 8

Item analysis

................................ ................................ ..................

5 9

Incongruities within responses

................................ .......................

6 1

Discussion of research questions

................................ ....................

6 2

Chapter Six:

Conclusion and Recommendations

................................ ......................

66

Summary

................................ ................................ .......................

6 6

Limitations of the study

................................ ................................ .

6 7

vii

Recommendations for future research

................................ ............

6 8

References

................................ ................................ ................................ .....................

70

Appendix A:

Informed Consent for Research Letter — Survey

................................ ...

7 7

Appendix B:

Survey Instrument

................................ ................................ ...............

7 8

Appendix C:

Survey Questionnaire Item Abstract Table

................................ ...........

81

Appendix D:

Informed Consent for Research Letter — Extended Questionnaire ........

8 2

Appendix E:

Extended Questionnaire

................................ ................................ .......

8 3

Appendix F:

Extended

Questionnaire Item Abstract Table

................................ .......

8 4

Appendix G:

Survey Responses — Summary Tables

................................ ..................

8 5

Appendix H:

Project Expenditures

................................ ................................ ............

9 1

1

Chapter One

Introduction

Context of the Study

O bservations of high school chemistry teachers‘ practices, and other anecdotal evidence, suggest that the use of classroom lecture demonstrations

is widespread. Chemical suppliers offer prepackaged kits, and even accredited courses, to encourage and support the inclusion of such demonstrations

in educators‘ daily practice

( Sharpen existing skills, 20 11) .

Chemistry and physics teachers at a number of school s employ attractive demonstrations to advertise course offerings and increase enrollment

( Chemistry Program Review , 2008), with some institu tions employing ― full - time resource [staff]

to develop, archive, and prepare lecture demonstrations‖

( The Mission of the YSU Chemistry Department, 2011 ) . Whether inclusion of classroom demonstrations truly advances students‘ interest and understanding remains unverified. The absence of published literature regarding the extensiveness and perceived effectiveness of lecture demonstrations

indicate s an opportunity for research to benefit current and future chemistry teachers and science education

programs.

Definition of Lecture Demonstration

Lecture demonstrations have been conducted in science classrooms for at least t hree

centuries. Taylor (1988) traces education via demonstrations of scientific principles to the late seventeenth century, with eminent figures such as Robert Hooke appointed as early as 1662 to act as demonstrators for F ellows of the Royal Society .

Taylor (1988 , p.

2

11 ) further states that ―public demonstrations as part of a course of instruction‖ ( which are presumably the equivalent of modern lecture demonstrations) began in 1694. There are certainly abundant references to classroom demonstrations illustrating specific scientific principles in academic literature of the int er v ening

centuries .

Mi chael Faraday used demonstrable phenomena as the basis of

his famous 1827 and 1860 - 61 lecture series

(see Faraday, 1904); more recently, texts such as those of Shakhashiri (1983, 1985, 1989, 1992 , 2011 a ), Sprott (2006), and Shmaefsky (2004) feature hundreds of demonstrations for high school and college students of chemistry and phys ics.

Kauffman (1996)

cites Jensen (1991) in claim ing

that early chemistry instruc tion was ―solely by demonstration ,‖

although Kauffman‘s (1996)

subsequent reference to the introduction of laboratory experience to students‘ education suggests that said d emonstrations were a part of lecture - based courses used in lieu of learners‘ laboratory work and not the sole means of introducing concepts. Regardless, Kauffman (1996) presents a detailed history of the lecture demonstration, including what he terms a ―g olden age‖ of scientific demonstrations presented for students, but also for members of the public.

Perhaps tellingly, one of the educators featured in Kauffman‘s (1996) article, Sir Humphry Davy, found that despite the consistent appeal of his demonstrat ion - laden lectures, the society gentlemen in attendance were not motivated to further pursue scientific endeavors.

Davy‘s

observation is in contrast to a statement by Taylor (1988) :

―it [lecture demonstration] seems to work with all age groups and is a great way of inculcating a sense of excitement about science.‖ The apparent contradiction is pa rt of the focus of the research

study .

3

Taylor (1988) defines a demonstration as an ―i llustration of a point in a lecture or lesson by means of something other than conventional visual - aid apparatus.‖ Presumably, laboratory investigations performed by students, although nominally covered under the aforementioned de script ion , would not be c onsidered ―demonstrations‖ ; we should amend the definition to explicitly state that the examples should be instructor - led , with students acting as a relatively passive audience rather than as participants . The resulting characterization appears to be a st andard interpretation of the meaning of ―lecture demonstration .‖

Purpose of the Study

The abundance

of information related to performing classroom science demonstrations is an unsubtle suggestion that educators who do not include attention - grabbing performances as part of their normal teaching are somehow remiss. M ost of the

published authors cited in this proposal presume that the use of science demonstrations is — or at least should be — practically univ ersal, with promoters emphasizing the ―charm‖ (Ramette, 1980) or ―entertaining distraction‖ (Shmaefsky, 2005) afforded by lecture demonstrations. Less convinced are Roadruck (1993) and Swanson (1999), who posit several credible reasons why some educators might choose not to include demonstrations in their instruction. Neither, however, presents any research data to validate the ir

rationales. Meyer et al. (2003) also suggest some reasons for educators not to employ lecture demonstrations, but offer

what a mounts to a straw - man argument

apparently designed to favor their use. For example, their

assertion that ― m any new teachers… have not been exposed extensively to the value and pedagogy

of demonstrations and are

4

uncomfortable with the thought

of conducting them in class ‖ implies that more experienced educators would most certainly incorporate lecture demonstrations — that unwillingness is merely due to teachers‘ inexperience, since the ―value‖ of demonstrations is self - evident. Meyer et al. (2003) at the same

time lament that ―[u] nfortunately, quantitative education research does little

to pr omote the use of demonstrations,‖ and are apparently unwilling to recognize that a lack of support for their assumption may indicate a flawed premise.

It may be that edu cators have chosen to include or exclude demonstrations from their repertoire based on their own experiences — as students or as teachers — in the classroom.

Data from the research study elucidate some of the reasons why teachers employ lecture demonstrations .

In particular, educators w er e asked about their experience

with demonstrations ;

concepts that are effectively taught using demonstrations ;

their familiarity with published research related to science demonstrations; and how — if at all — they expect to alte r their use of lecture demonstrations in their classrooms.

Survey data , along with additional data from extended questionnaires,

were therefore collected in order to address the following :

Primary Research Question s

RQ1.

Do high school chemistry teachers routinely employ

classroom demonstrations as part of their instruction ?

RQ2.

Do high school chemistry teachers perceive students‘ performance to be

improved by the use of classroom demonstrations ?

5

RQ3.

Do high school c hemistry teachers perceive students‘ motiva tion to be enhanced by the use of classroom demonstrations?

RQ4.

Is there a

correlation between chemistry teachers‘ exposure as students to lecture demonstrations and their

current use of classroom demonstrations ?

RQ5.

Is there a correlation between teachers‘ years of chemistry teaching experience and their use of classroom demonstrations?

RQ6.

Is there a correlation between chemistry teachers‘ academic preparation (chemistry vs. ―non - chemistry‖ degree) and their u se of classroom demonstrations?

Minor Research Question

RQ 7 .

What best - practice research related to classroom demonstrations guides

high school chemistry teachers ?

Significance of the s tud y

Published

literature mentions little

about how extensive the use of lecture demonstrations in chemistry classrooms has become in the deca des since their introduction. Demonstration s‘

advocates and skeptics alike are therefore expect ed to benefit from the mixed - methods research

study , which seeks to both quantify the means by and extent to which lecture demonstrations are employed in high school chemistry classes and to elucid ate the perspectives of a representative cross - section of educators. T he resulting survey data indicate chemistry tea chers‘ perceptions of the effect of classroom demonstrations on students‘ learning and motivation to study the subject

6

further. C orrelations among educators‘ years of science teaching experience, past exposure to lecture demonstrations, and frequency of t heir inclus ion of demonstrations in their own teaching are

indicated

from analysis of quantitative data.

7

Cha pter Two

Literature Review

Introduction

Educators at all levels have ready access to information regarding classroom demonstrations. There is clearly much discussion devoted to the use of science demonstrations, including differences of opinion reg arding their merits (see Beall, 1996) .

The first section of the literature review will highlight some of the published justifications for the use of classroom demonstrations . Subsequent sections will discuss scholarly articles focused on various perceived benefits of lecture demonstrations, including greater motivation to learn the subject matter, improved understanding of concepts, and effective s ubstitutes for active laboratory experience.

Justif ications for use of demonstrations

A s earch of Internet resources produces a large number of sites dedicated to sharing science demonstrations, including those maintained by

individuals (e.g. Spangler, 2010) whose careers are based on presenting demonstrations and marketing supplies for others to employ in the classroom. The author has

already made reference to some of the texts (perhaps the best known of which are those of Shakhashiri) that are readily available to science educators; such

publications typically provide detailed lists of necessary chemicals and apparatus in addition to

discussion s

of the concepts exhibited in the demonstrations.

8

Along with the recipes for pre sentation, the texts and Web sites

proffer a philosophy underlying the use of classroom demonstrations: that because demonstrations are entertaining, they will

spark deeper

interest in the current topic and prompt

students to further study the subject.

M any published articles relating to demonstrations take

up this theme; for example, Meyer et al. (2003) state that ― educators can generate and renew vital interest in

chemistry through the use of well planned and effectively

presented classroom demonstrations that attract and engage

the active and visual learners in today‘s classrooms . ‖ R amette (1980) , whose article is quoted extensively by Shakhashiri (1983), states that ―the teacher who does not take advantage of demonstrations is doing his st udents a disservice‖

by failing to

stimulate excitement in the audience.

There are certainly valid reasons for including demonstrations in introductory science courses; Swanson (1999) highlights one ostensible

benefit to learners: ―[j] ust as an artist u ses a paintbrush to reveal an underlying concept, a science educator uses a demonstration as his or her tool to illustrate scientific principles.

In both cases, the picture is worth a thousand words.‖

Milne and Otieno (2007) have found lecture demonstrat ions important in forging personal relationships between the instructor and students, particularly for ―urban students belonging to marginalized groups‖, where the inclusion of lecture demonstrations produced greater student engagement during, and after, t he introduction of concepts. Shakhashiri (2011b) , too,

promotes the use of demonstrations to enhance learning by strengthening interpersonal relationships:

[w]hat we want to do is make connections. This is how we help our brain[s] change — by making connections. I want you to know why I, and many others, use chemical demonstrations to connect with people…do you see the potential for connections? … These connections are used to inform…engage…educate… advocate…[and] persuade.

9

O ther justifications demand

scrutiny, such as Swanson (199 9)‘s assertion that

[d]emonstrations provide teachers with a way to motivate students to learn and retain knowledge of chemistry ‖ and an impassioned declaration from Bent and Bent (1980):

[l] ecture experiments make chemical l ectures demanding for lecturers, meaningful for philosophers, and interesting for students.

They are highly motivational.

They have immense heuristic value, tremendous rhetorical power, overwhelming persuasive force…If you don‘t see it, you won‘t believe

it.

And if you don‘t believe it you won‘t understand it.

And if you don‘t understand it, you won‘t long remember it.

The senses are important, not only for first discovering, but for receiving knowledge …

In particular, the converse of Bent and Bent‘s

contention (that seeing leads to understanding) should not be presumed true, although it appears to be th e basis for many demonstrations .

Increased student motivation

D efinitions of motivation tend to be nebulous , and it is therefore prohibi tively difficult to validate or refute any claims regarding the

motivational effects of science demonstrations. Shakhashiri‘s

(2011b) remarks could be construed as a claim that demonstrations lead to greater understanding of concepts, but could also be interpreted to mean that the relationships formed between the presenter and members of the audience, rather than the presentatio n itself, beget increased motivation to learn. Students‘ self - reported ― motivation ‖ , however, is typically an indication of immediate interest — what Schraw and Lehman (2001) term ―situational interest …spontaneous and context - specific ‖ — rather than of genuin e desire to study and understand the underlying principles

(defined by Schraw and Lehman (2001) as ―personal interest …enduring and context - general ‖).

10

The question of whether situational interest

in

a demonstration equates to improved desire to understand

course topics and attraction toward further study of the subject remains largely unaddressed in the literature. While Bent and Bent (1980) and Swanson (1999) conflate the immediate appeal of an attention - grabbing d ivers ion with long - term understanding of

the underlying principles , Schraw and Lehman (2001) ‘s metastudy indicates that

personal interest is n ot highly malleable.

Lecture demonstrations may well increase situational interest, commanding attention to the color changes, explosions, and other allu ring features of chemical demonstrations , but Schraw and Lehman (2001) f ind that, at least in some instances,

such ―seductive details (i.e. highly interesting, but unimportant information )‖

interfere with recall of more important information.

Waldman , Schechinger, and Nowick

(1996), Ramette (1980),

Schrempp

(200 8 ) , and Haddock et al. (2008) are but a few authors who claim that exhibit ions they conduct or promote lead to greater attention devoted to the principles being demonstrated , although none provid e

research - based evidence to support their contentions.

Publication

of such assertions implies

a tacit endorsement of the claims , but

testimonials, no matter how numerous or supportive, are inadequate su bstitutes for valid studies. Even Pierce and Pierce (2007), who are quite critical of demonstration - based instruction, apparently feel compelled to tout the ―remarkable attention‖ that students pay

to chemistry demonstrations, and declare that ―[d] emonstr ations help instructors provide motivation and

inspiration in lecture classes, especially at introductory levels ,‖

without citing any source for this significant statement.

11

Perhaps Pierce and Pierce are

simply acknowledging the entertainment value

of dem onstrations , and are defining ―motivation and inspiration‖ as

students‘

attendant interest — however

fleeting — in the spectacle before them .

Other authors are more direct about their beliefs regarding the value of demonstrations .

Ramette (1980)

states that ,

― [g] ood demonstrations not only spice up a class session, but they also help to teach principles, and they help to build up general experimental knowledge of a sort which makes chemistry seem more real and less abstract , ‖

and mentions ―opportunities for teaching through classroom demonstrations . ‖

S hmaefsky (2005)

and Pierce and Pierce (2007) present a more qualified view of the efficacy of lecture demonstrations, cautioning educators to be aware of current research into e ffective demons tration assessment techniques.

Increased student learning

Even Ramette (1980), an early champion of demonstrations as a means of engagement, acknowledges that demonstrations should serve a purpose other than transforming teachers into ―c lowns in the classroom ,‖

and there appears to be scholarly consensus regarding the necessity of shifting learners from passive observation toward a ctive construction of knowledge.

Opportunities remain for research into the most effective means of introduc ing or reinforcing concepts using lecture demonstrations; Glasson (1989), Roth, McRobbie, Lucas, and Boutonn é

(1997), Lynch and Zenchak (2002), Fagen (2003), Meyer et al. (2003), Shmaefsky (2005), Pierce and Pierce (2007), and Baddock and Bucat

(2008) all recommend somewhat different procedures for

12

presentation methods and assessment of learning , and present differing outcomes from the methods they have examined.

It is not unreasonable for educators to expect improvements in students‘

understand ing as a result of lecture d emonstrations — educators apply particular instructional methodologies with the presumption that said

techniques will lead to learning gains.

A study published by House (2000)

correlates

data obtained by interviewing a large samp le of 13 - year - old students in Hong Kong with their performance on the 1999 TIMSS (Trends in International Mathematics and Science Study) exam. In the study, House determined

that various instructional

strategies , including classroom demonstrations , produc ed

a significant effect on students‘ learning.

In

particular , multivariate regression

analysis suggests that demonstrations by themselves (i.e. in the absence of other beneficial

instructional techniques)

account for a small percen tage of the variance in the exam scores .

The study does not, however, provide any detail regarding the definition

of ―demonstration‖ apart from its characterization as an

activity

performed by the teacher .

Crouch, Fagen, Callan, and Mazur (2004) state that lear ners must be actively engaged in order to realize gains in conceptual understanding; although t he research of Buncick, Betts, and Horgan

(2001) indicated increased student engagement, measures of performance and motivation (attitudinal) gains were inconclu sive.

Pierce and Pierce (2007) describe favorable learning outcomes arising from the use of demonstration assessments, wherein significant learning gains were produced on assessment items directly related to demonstrations as long as the demonstrations we re unconnected to laboratory topics. Interestingly, midterm and final exam scores indicated that the Pierce

13

and Pierce‘s treatment group — students who completed written post - demonstration assessments — did not perform better than the control group, and, on t wo of the three post - treatment exams, performed significantly worse.

Silberman (1983)

discusses a

deleterious effect of chemistry demonstrations, highlighti ng students‘

explanations

of a common demonstration that illustrate their persistent misconceptions and apparent disinterest in determining the real explanation for observed phenomena.

These findings are not the result of formal research, but Silberman‘s recommendations (―do

[i.e. perform] …better demonstrations and…question students‘ understanding in or d er

to improve observational and interpretive skills‖) are similar to those of later investigators such as Shmaefsky (200 5) and Baddock and Bucat (2008) .

Clermont, Borko, and Krajcik ( 1993, 1994) suggest that improperly - performed demonstrations may lead t o the introduction and entrenchment of misconceptions; a particularly attractive demonstration, explained incorrectly, may be harmful to students‘ understanding.

Considerable research investigating the effectiveness of various demonstration techniques in fostering learning gains has been conducted in the past decade, much of it skeptical. According to Fagen (2003),

[s] tudent evaluations suggest that demonstration s do serve to entertain and

involve students in the lecture; one study found demonstrations to be among students‘

favorite elements of introductory undergraduate physics courses … [h] owever, there is less evidence indicating that lecture demonstrations help

students

understand the scientific principles underlying the demonstration.

While instructors and

students alike claim that students learn from demonstrations … there is little actual data to sup port this claim.

14

Substitutes for laboratory experiences

Swanson (1999) suggests that demonstrations are sometimes necessary substitutes for students‘ laboratory experience . Others, though clearly

supportive

of the use of lecture demonstrations ,

are

less bold.

Beall (1996) comments:

―[d]emonstrations have ped agogical value but are not an end in themselves… [they] are only one of many teaching techniques and shouldn‘t be used for their own sake .‖ Roadruck (1993), citing the writings of cognitive theorist Piaget, flatly states that ― d emonstrations should not be a

substitute for the hands - on laboratory work .‖ Whether teachers of high school chemistry

courses share this view of the purpose and value of classroom demonstrations is a focus of the proposed study; a dearth of information on this topic is evident.

Sum mary of, and d eficiencies in, literature

Published articles regarding lecture demonstrations address the putative

reasons for their inclusion in chemistry pedagogy. The absence of a solid research basis for claims of increased student learning and motivation, however, calls those

claims into question. R esearch that might provide evidence to support or refute such contentions begins with the

determination o f why, and how often, classroom demonstrations are used by high school chemistry teachers.

One cannot reasonably determine the effectiveness

of

classroom demonstrations

without a

sense of their prevalence; t he literature , however,

is silent with respect to

the extent to which lecture demonstrations are employed in high school and college classes. The research described

herein, then, a ttempt s

to articulate

the frequency and

15

methodology of use, as well as the intended

purpose s

and means of assessment, of dem onstrations in high school chemistry

classrooms.

While m easurement of gains produced by the use of lecture

demonstrations

may be the focus of further research, a sense of the perceived benefits arising from their inclusion in classroom instruction should provide an effective starting point for such investigations.

16

Chapter T hree

Methodology

Introduction

The purpose of the mixed - methods study is to address the research questions regarding

the extent to which lecture demonstrations are used ,

and the ir

perceived effects on students‘ understanding and motivation. While

quantitative finding s

from survey data reveal definitively the extent to which classroom demonstrations are employed and educators‘ beliefs regarding their effic acy, selection of scaled - response items inadequately convey s

teachers‘ ration ales for their convictions. A

sequential explanatory mix ed - methods study, wherein

qualitative interview s

are utilized

to illuminate detail underlying

previously - collected

quantitative survey

data , is therefore warranted for the research

study (Creswell & Plano Clark, 2007; I vankova, Creswell, & Stick , 200 6 ) .

I nterviews of those whose survey responses exhibit anomalous data provide necessary context and ―evidentiary power‖ (Sandelowski, 2003, in Plano Clark & Creswell, 2008, p. 327) , while inclusion of perspectives from those whose response set s

are

more represe ntative

of overall findings adds confirmatory power to the conclusions drawn from the survey data .

Population and sample

Th e sample frame for the investigation

consisted

of high

school chemistry teacher s working in the United States. A list of three hundred potential survey participants was populated by first choosing the state from which a high school would be

17

selected, using a random number generator and the most recent national census data so that the chance of a state‘s selection w as proportional to its population. Once a state had been chosen , a high school was selected from a comprehensive national database ( accessible online at http://schooltree.org/high/ ) , using another random number with boundaries set such that each high school in the state had an equal chance of selection. Following the identification

of the high school, each chemistry teacher at the institution was given an equal chance of selection, either by random choice

from a list published on the school‘s Web site, or — when insufficient data were available online — by asking the switchboard operator at the school to randomly choose an individual from the available pool of chemistry teachers. If the

identified high school had no chemistry program, or was no longer operating, an entirely new selection of state and high school was performed to replace it.

The first fifty individuals (including two selected to replace defunct schools) from the list of t hree hundred were contacted and offered the opportunity to participate in the study. Thirty - three of the initial fifty teachers contacted returned survey data, with one returning the cash compensation along with the uncompleted survey instrument. The 66 . 0 % response rate from the initial mailing suggested that surveys collected from forty more contacts should suffice to complete the data set (a minimum of fifty completed surveys) . Consequently, f orty more teachers were then selected

in sequence from the l arger list, and sent the same compensation and research documents

as were provided to the initial set of contacts.

One of the surveys sent to the second group was subsequently returned as undeliverable. Twenty

of the thirty - nine teachers

contacted in the

second mailing — 5 1 .3 % of those to whom the instrument was sent — returned completed surveys;

18

one of th ose

respondents, although identified by his school as a chemistry teacher, indicated throughout the survey responses that he was instead a teacher of physic s.

Variables and measures

Eight of the fourteen

survey questions (see Appendix B) were quantitative, using balanced Likert scale items to assess perceived effects of lecture demonstrations on students‘ performance and motivation. The remaining

Full document contains 99 pages
Abstract: While lecture demonstrations have been conducted in chemistry classrooms for hundreds of years, little research exists to document the frequency with which such demonstrations are employed or their effect on learners' motivation and performance. A mixed-methods research study was performed, using quantitative and qualitative survey data, along with qualitative data from follow-up interviews and structured correspondence, to determine the extent to which lecture demonstrations are used in high school chemistry instruction, and the perceived effects of viewing such demonstrations on students' performance on course assignments and on motivation to excel in current and future chemistry courses. Fifty-two randomly selected chemistry teachers completed a survey regarding their present and projected use of classroom demonstration. Twelve of the survey participants provided elaboration in the form of an extended questionnaire. Data indicate that all except one of the survey participants currently employ lecture demonstrations, and all anticipate performing the same amount of, or more, demonstrations in their future instruction. Extended questionnaire and survey data reveal that the participating chemistry teachers perceive substantial positive effects on students' performance on classroom assignments and a lesser, though still positive, effect, on learners' motivation. No correlations were observed between the number of lecture demonstrations performed and educators' years of experience teaching chemistry, previous exposure to demonstrations, or undergraduate degrees earned.