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Chemistry Teachers ^ and ChemistryStudents5 Perceived Advantages andDisadvantages of High SchoolChemistry LaboratoriesJeffrey R. LehmanDepartment of Teacher EducationState University of New York at AlbanyAlbany, New York 12222

Reviews of research on the role of the laboratory in science are evidence ofeducational researchers* interest in laboratories as an instructional mode(Bates, 1978; Hofstein & Lunetta, 1982). Moreover, Gabel, Samuel, Helgeson,Novak, and Butzow (1986) recently reported that high school science teachersranked research related to the science laboratory as their number one researchinterest in science education. While various studies have been conducted toexamine the effects of laboratory experiences on students’ attitudes (Ben Zvi,Hofstein, Samuel & Kempa, 1974), cognitive outcomes (Kozma, 1982), andpsychomotor skill development (Beasley, 1985), little research has beenconducted to assess science teachers’ perceptions and the perceptions of theirstudents on laboratory activities. To some extent, the effectiveness oflaboratory activities may be linked to teachers’ and students’ perceptions ofthe activities. Thus, the following study was designed to collect data from highschool chemistry teachers and their students to answer two questions.

1. What do chemistry teachers perceive as advantages and disadvantages oflaboratory activities?

2. What do chemistry students perceive as advantages and disadvantages oflaboratory activities?

It was anticipated that a reporting of this descriptive data would not onlyproduce questions for future research but also provide implications for scienceteachers in an area that they have identified as a research priority (Gabel,Samuel, Helgeson, Novak, & Butzow, 1986).

Procedure

Recently, a national sample of 500 high school chemistry teachers weremailed a questionnaire designed to collect data about the nature and extent oftheir laboratory use. In addition to completing the entire questionnaire, theteachers were requested to have their students answer the two items thatfocused on perceived advantages and disadvantages of laboratory activities.An initial mailing and a follow-up mailing resulted in 295 teacher returns.Forty-four of these teachers also returned responses from 1570 chemistrystudents. The data from these two items for the 44 chemistry teachers (averageyears of teaching experience = 12.5) and their students will be reported here.

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Two science education graduate students independently categorized theteachers’ and the students’ responses to the two constructed response itemsthat requested teachers and students to identify perceived advantages anddisadvantages of laboratory work. Inter-rater agreement for the categorizationof these responses was 87%.

Results

Teachers’ and students’ perceived advantages of laboratory activities couldbe placed into one of four categories: affective, psychomotor, cognitive, orprocess. The percentage of teachers and students listing statements in thesecategories as well as example statements from each category appear in Table1. Similarly, perceived disadvantages were placed into one of five categories:time, expense, safety, management, or content (Table 2).

Chemistry Teachers

The most frequently stated advantage of laboratory activities related to thecognitive domain. Teachers thought that laboratory activities helped studentslearn chemical concepts and principles and reinforced class lectures. Theamount of time that it took for teachers to prepare laboratories and the

Table 1

Frequencies of Perceived Advantages of Laboratory Activities by ChemistryTeachers and Chemistry Students

Teachers StudentsCategory/Example Statements % (n=44) %(n==1570)

Affective 34.1 22.11. Laboratories are fun2. It helps keep the person’s interest3. An advantage is learning to work with others

Psychomotor 20.5 26.61. It gives you insight on how to use the equipment2. You are able to get hands-on experience

Cognitive 63.6 75.31. If you do and watch something happen, you will

remember it better2. It helps us learn the material from class3. You can apply concepts you have been studying

Process 20.5 11.51. You get to observe, predict, draw conclusions2. It helps us have an orderly method of gaining

knowledge

Note: Percentages do not add to 100% since respondents could list morethan one advantage.

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amount of time that students had to complete the activity were the mostfrequently mentioned disadvantage. About 45% (n=20) of the teachers alsoidentified safety considerations as a disadvantage.

Chemistry Students

Like their teachers, chemistry students most frequently listed cognitiveoutcomes as a perceived advantage, although 351 (22%) students indicatedthat laboratories were difficult to understand and they often did not knowwhat they were doing or why. The most frequently stated disadvantage,however, was the students’ concern for their safety.

Table 2

Frequencies of Perceived Disadvantages of Laboratory Activities by ChemistryTeachers and Chemistry Students

Teachers StudentsCategory/Example Statements % (n=44) Vo (n= 1570)

Time 56.8 22.61. Labs take too much time to plan2. There is not enough time to finish, so we hurry3. Labs take up all the class time so we have to do

all of the questions out of class

31.8 8.1Expense1. It takes a lot of money to do the experiments

Safety 45.5 39.21. It could be dangerous if students aren’t careful2. There are so many precautions to take3. We don’t understand all of the possible effects of

the chemicals�we may learn in the future thatsome of the chemicals are carcinogenic

Management 15.9 7.51. Some people mess around, don’t do the lab, cheat2. Some students feel that it’s a free day�too much

goofing off

Purpose/Goal/Contenf 20.5 22.41. They are too complicated�they think we are all

Al Einsteins2. They don’t always turn out correctly and it can

contradict what you have read and confuse you3. You just do what a lab or teacher says, but you

don’t know what exactly or why you’re doing it.

Note: Percentages do not add to 100% since respondents could list morethan one disadvantage.

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Discussion/Implications

When asked to identify perceived advantages and disadvantages oflaboratory activities, chemistry teachers and their students listed responses thatclustered into a rather small number of categories. Both teachers and studentsmost frequently perceived cognitive advantages of laboratory activities. Thenotion that laboratories help students understand the abstract concepts andprinciples introduced in class was frequently expressed. If this perception is avalid one, it supports the position that many past research studies have usedinstruments that were not sensitive enough to adequately assess outcomes inthe laboratory environment (Hofstein & Lunetta, 1982). Alternatively, teachersand students might have misconceptions about the value of laboratoryactivities to increase cognitive understanding. Interestingly, 351 (22%) studentsindicated that they frequently did not know what they were doing inlaboratories, what the purpose of specific laboratories was, or were oftenconfused by the results. It appears that these students would benefit fromadditional prelab and postlab instruction where teacher and studentsspecifically identify relationships between the laboratory activity and contentpresented before and after the activity. Since some students perceivedlaboratories as helping them understand chemistry content and othersperceived the opposite, future research that attempts to determine whetherstudents with varying aptitudes benefit differentially from laboratoryexperiences appear warranted.A frequently mentioned disadvantage by both teachers and students was the

time element of laboratories. Both groups of respondents indicated thatstudents were often rushed in order to complete a laboratory activity. Thisapparent lack of sufficient time can be partially explained by considering thenature of chemistry laboratory activities. Such activities often involvechemicals, equipment, and procedures that students have limited experiencewith (i.e. chromatography, titration, etc.). Thus students are faced withattempting to follow directions, learning to manipulate equipment, collectingdata, and integrating the data with prior knowledge. When attempting toperform such a complex activity, students might feel rushed. While not alwayspractical or possible, activities that can be started on one day and completedthe next could be emphasized more in preservice and inservice training. Forexample, students could acquire and assemble all materials needed to performa distillation activity one day and then perform the investigation the followingday.Another aspect of time as a disadvantage was both groups’ indication

thatlaboratories take away from class time. This perception suggests that someteachers and students feel that laboratory activities are an add-on type ofactivity. If the perception is that laboratories are a necessary evil, then thereprobably will be minimal links made between the activities and otherchemistry content. In addition to science processes and products, it appearsthat the nature of science must be continuously reinforced as an objective of

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science education. In this way, the integral role of laboratory work in sciencedisciplines may be more clearly perceived.A second frequently perceived disadvantage by both groups was safety.

Since many laboratory activities require students to handle chemicals, thisconcern is somewhat self-evident. Whether students in other science subjectareas would express a similar concern remains to be determined.

Conclusion

Chemistry teachers’ and their students* perceived advantages anddisadvantages of laboratory activities were reported. Whether or not similarperceptions exist for other science subject areas is yet to be explored.Although not examined in this study, the effectiveness of laboratory activitiesmay be related to teachers’ and students’ perceptions of them. For example, ifstudents perceive the development of psychomotor skills as the primarypurpose for laboratories and as a result devote a majority of their behavior toattain this goal, they would have less time to analyze, interpret, or integratethe data they are collecting during the activity. On the other hand, if studentsperceive obtaining a correct answer as the purpose for laboratory work, theninquiry and other skills may be overlooked. Both scenarios suggest thatoutcomes of laboratory activities might depend upon students’ perceptions ofthe tasks that they are completing. Teachers are encouraged to collectperception data from their students and to engage students in a dialogueconcerning the role of the laboratory in science.

References

Bates, G. (1978). The role of the laboratory in science teaching. In M. B.Rowe (Ed.), What research says to the science teacher (Vol. 1). Washington,DC: National Science Teachers Association.

Beasley, W. (1985). Improving student laboratory performance: How muchpractice makes perfect? Science Education, 69, 567-576.

Ben Zvi, R., Hofstein, A., Samuel, D., & Kempa, R. (1976). The attitude ofhigh school students to the use of filmed experiments in laboratoryinstruction. Journal of Chemical Education, 53, 575-577.

Gabel, D., Samuel, V., Helgeson. S., Novak, J., & Butzow, J. (1986).Research interests of secondary science teachers. Journal of Research inScience Teaching, 23, 145-163.

Hofstein, A., & Lunetta, V. (1982). The role of the laboratory in scienceteaching: Neglected aspects of research. Review of Educational Research,52, 201-217.

Kozma, R. (1982). Instructional design in a chemistry laboratory course: Theimpact of structure and aptitudes on performance and attitudes. Journal ofResearch in Science Teaching, 19, 261-270.

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