Peer instruction in chemistry education: Assessment of students’ learning strategies, conceptual learning and problem solving

A two-group, pretest and posttest, quasi experimental design was conducted in this research (Fraenkel & Wallen, 2009). Pretest and posttest evaluation before and after the implementation were conducted on the experimental group (EG) and the control group (CG). The research design is presented in Table 1. The details of implementation were explained in the instructional approaches and data collection section, respectively.

Table 1. The Research Design

Groups	Pretest	Implementation	Posttest
EG	CAT, LSS	PI	CAT, LSS
CG	CAT, LSS	CI	CAT, LSS

Note: CAT: Chemistry Achievement Test; LSS: Learning Strategy Survey; PI: Peer Instruction; CI: Conventional Instruction

Participants
The research was conducted at Dokuz Eylul University, Izmir, Turkey. The age of students was between 18 and 22. The research sample consisted of 47 freshman students from two different chemistry classes. The EG composed of 22 students and the CG consisted of 25 students. The students’ academic background in both groups was investigated and it was found that the difference was not statistically significant.

Instructional Approaches
The experimental group students were instructed with peer instruction (PI), which is based on constructivist approach, and the control group students were instructed with conventional instruction (CI). Two groups were taught by the same instructor. Some possible limitations of the research were listed as follows; the sample size of the research was small and the research only was applied to chemistry course. Primary objectives of the course were to accustom the students to describing and explaining the fundamental principles and concepts of chemistry. The details of peer instruction and conventional instruction were given respectively.

a) The instructor gives the recitation section. The sample course procedure of peer instruction was presented in Table 2.
b) Time is given to the students to consider the concept test.
c) They indicate their responses individually.

Colored flashcards (A-red, B-yellow, C-green, and D-blue) are used to indicate the students’ answers during the voting process. Low technology (flashcards) instead of high technology (classroom response systems) was used due to limited financial resources.

d) They debate their responses with their peers.

If the percentage of correct answers is between 30% and 70%, then the instructor starts the discussion. If the percentage of correct answers is lower than 30%, the concept test(s)/problem(s) is reexamined.

Identical concepts were presented to the EG and the CG. The control group students are monitored in the following procedure. The instructor gives a brief explanation. The students are given time to examine the concept tests. They show their individual responses. The students use the flashcards during the voting process. Finally, general feedback to the students by examining the correct responses is provided by the instructor.

Concept tests designed by the authors were edited to be multiple-choice test questions. Some concept tests were chosen from the literature (Brown, LeMay, & Bursten, 1997). The concept tests mirrored the course goals. Students were given four or five concept tests (easy, medium, and difficult) which they answered in a 75 minute block-class.

It should be noted that similar concept tests were answered and discussed in the class and in the chemistry achievement test to prevent pseudo-enhancement in the research results. The difficulty levels of the concept tests were adjusted to equal the protocol presented by Reay, et al., (2005) and Smith, et al., (2009). Designed concept tests were prepared from lower to higher order thinking skills (Cook, Kennedy, & McGuire, 2013). Easy concept tests were based on remembering or understanding. Medium concept tests were based on applying or analyzing. Difficult concept tests were based on evaluating or creating. An isomorphic question (Porter, et al., 2011) as an alternative to the medium or difficult concept test with the same difficulty level was also prepared.

Table 2. Sample Course Procedure of PI

Time	The Process of PI	Activities
0-20 min	The instructor gives the recitation section.	Recitation -20 min-
21 min	The instructor gives the first concept test to the class.	First Concept (Easy) Test - 6 min-
23 min	Time is given to students to consider the concept test.
24 min	The students indicate their responses individually.
26 min	If the percentage of their correct answers exceeds 70%, then the instructor explains the concept in detail.
27 min	The instructor gives the second concept test to the class.	Second Concept (Medium) Test -9 min-
29 min	Time is given to students to consider the concept test.
30 min	The students indicate their responses individually.
32 min	If the percentage of their correct answer falls between 30% and 70% the instructor initiates a peer discussion section. The students debate their responses with their peers.
33 min	Students declare their revised responses.
35 min	If the percentage of revised answers exceeds 70%, then the instructor explains the concept test.
35-50 min	The instructor continues the recitation section.	Recitation -15 min-
51 min	The instructor gives the third concept test to the class.	Third Concept (Difficult) Test -15 min-
53 min	Time is given to Sstudents to consider the concept test.
54 min	The students indicate their responses individually.
56 min	If the percentage of their correct answer is lower than 30% the instructor informs about the concept test.
57 min	The instructor gives the concept test to the class again.
59 min	Time is given to students to consider the concept test.
60 min	The students indicate their responses individually.
62 min	If the percentage of their correct answer falls between 30% and 70% the instructor initiates the peer discussion section. The students debate their responses with their peers.
63 min	Students declare their revised responses.
65 min	If the percentage of revised answers is higher than 70% the instructor explains the concept test.
66 min	The instructor gives the isomorphic concept test.	Isomorphic Concept Test -6 min-
68 min	Time is given to students to consider the concept test.
69 min	The students indicate their responses individually.
71 min	If the percentage of their correct answer is higher than 70%, the instructor explains the concept in detail.
75 min	The instructor finally summarizes the subject.	Summary -4 min-