Spatial Validity based Compact Clustering

The following seven research instruments were used in this study:

(A) Response instruments

1 Physics Achievement Test (PAT)

2 Students‘ Physics Self-Efficacy Questionnaire (SPSQ) 3 Science Process Skills Worksheets (SPSW)

(B) Observational instrument

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4 Classroom Activities Evaluation Rating Scale(CAERS) (C) Stimulus instruments

5 Teachers‘ Instructional Guide on Problem Based Learning strategy (TIGPBLS).

6 Teachers‘ Instructional Guide on Interactive Invention Strategy (TIGIIS).

7 Teachers‘ Instructional Guide on Conventional Lecture Method (TIGCLM).

3.4.1 Physics Achievement Test (PAT)

This is a researcher developed multiple choice objective test, made up of forty items. Each item has one correct option and four distractors. The instrument tested the pre-service teachers‘ intellectual achievement in ferromagnetism, electromagnet, force effect of current- carrying-conductor in magnetic field and electromagnetic in-duction.

The scoring of items of PAT was done on a dichotomous basis. The correct re-sponse earned one mark while an incorrect rere-sponse earned zero. To reduce guessing of the correct answers five options were used and students were given enough time to work on the questions. Items of the test were formed from a test blue print on table 3.2 showing cognitive domain of Blooms‘ taxanomy of knowledge, comprehension, application, analysis, synthesis and evaluation and the contents covered.

Table 3.2: Table of Specification for PAT

Topic Knowledge Comprehension Application Analysis Synthesis Total

Ferro-magnetism

4 3 1 2 3 13

Electro-magnet

1 1 1 1 2 6

Force effect of current carrying con-ductor

5 3 6 2 2 17

Electromag-netic induc-tion

1 2 - 1 - 4

Total 11 9 7 6 7 40

Originally the researcher constructed a test with eighty items for PAT. To es-tablish PAT content and face validity, copies of the initial test draft that contained

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eighty (80) items were given to three physics educators and modifications based on their suggestions were made. This led to the dropping of nine items. The seventy one (71) item test was thereafter administered on thirty four (34) NCE III students in a representative College of Education outside the sample used. The reactions of the stu-dents to the test were noted and the result used for item analysis. The test item analy-sis provided baanaly-sis for reducing the test items to forty (these were items with difficulty indices between 0.35-0.75). The forty (40) items were administered on another sixty (60) NCE III students and the results were analyzed using Kuder-Richardson formula 20. The reliability index obtained was 0.875.

3.4.2 Students’ Physics Self Efficacy Questionnaire (SPSQ)

A general self-efficacy questionnaire was adopted from Ashimalowo (2006) and modified by the researcher to measure students‘ self-efficacy in physics. This consists of ten (10) items to be graded based on four point Likert scale ranging from Strongly Agree, Agree, Disagree and Strongly Disagree. The positive statements were graded 4,3,2,1, respectively while the reverse was the case for the negative statement thus clearing out the undecided column in order to commit students to either the posi-tive or negaposi-tive side of the issues.

The instrument was given to three experts in the department of educational Psychology for their expert advice in respect to the language level, suitability and over all face validity of the instrument, based on their input, corrections were made.

Also, the instrument was given to my supervisor who read though to make the final modifications. Then, the instrument was administered to 60 N.C.E III students who were not part of the main study. The reliability coefficient of the instrument was cal-culated using the Cronbach alpha method and the value obtained was .9561 indicating that the instrument was reliable.

3.4.3 Science Process Skills Worksheets (SPSW)

Science process skills assessment was based on skills which are discernible from written scripts or those which may be inferred from such scripts. Work sheets were developed by the researcher to assess the pre-service teachers‘ science process skills during every lesson for the different experimental groups. Interactive invention strategy treatment group and the conventional lecture method group used the same worksheets which has five items each with four points to be completed by the students

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during the lesson. Two marks were awarded to each of the four points making a total of forty marks But the worksheets for those in problem-based learning group were slightly different because it incorporated few items of the inquiry process used in that study group. Each contained eight items three of which assessed their ability to inves-tigate on how to solve the given problem while five assessed ability to observe, iden-tify, classify, measure, formulate hypothesis, gather data, test hypotheses, and making inference based on data collected. Five marks were awarded to each item making a total of forty marks. These worksheets were given to the supervisor to read and make necessary corrections to ascertain the face validity of the instrument. These work-sheets were given to each participant during every lesson to fill during the lesson as they are interacting with the materials.

3.4.4 Classroom Activities Evaluation Rating Scale (CAERS).

This is to measure the pre-service teachers‘ classroom practice and the teach-er-students‘ interactive activities and was adapted from Omosehin (2004) and made into two scales. The first one measured the instructors adherence to the teachers‘

guide given and was used during the training period and during lessons by the two research assistants. The second measured the pre-service teachers‘ involvement dur-ing the lessons and also items dealdur-ing with group activities and whole class activities involving teacher and the students. Group activities involving the teacher included placing students in mixed-gender and self-efficacy groups, assigning specific roles to students and monitoring students‘ interactions.

The ones involving students included asking each other some questions, per-forming specific roles and challenging each others‘ reasoning and conclusions. For the whole class activities, teacher‘s activities included passing facts and information, giving direct instructions, demonstration with apparatus among others, while the stu-dents‘ activities include listening attentively as well as asking and answering ques-tions and carrying out experiments. The activities were scored on a four-point scale ranging from zero (0) to three (3).

To establish the content and face validity of this instrument, copies of the first draft were given to experts in the field of education especially in the area of classroom observation for necessary comments as regards the instrument. Based on their com-ments, wordings of some items were changed and some items were droped. The inter-rater reliability index of the instrument was estimated using Scott‘s п. Reliability

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dex of 0.76, 0.71 and 0.82 were obtained for teachers‘ classroom rating scale, prob-lem-based learning group and interactive invention group respectively. These instru-ments were given to the research assistants to complete as the classes were in pro-gress. This was to motivate the groups to be serious knowing that they were being graded but the scores obtained were not part of the final grading of the participants.

3.4.5 Teachers’ Instructional Guide on Problem-Based Learning Strategy (TIGPBLS).

This outlines the steps involved in presenting the PBLS package to the pre-service teachers in problem based learning group (Experimental group I); it has three phases: (i) Problem presentation by the instructor (ii) Self–Study / research, students work on issues. (iii) Class presentations and summary/conclusion.

3.4.6 Teachers Instructional Guide on Interactive Invention Strategy (TIGIIS) This outlines the steps involved in presenting the course content to the stu-dents in interactive invention strategy group (Experimental group II). It has the fol-lowing steps (i) Review of previous lesson (ii) Over view of the day‘s lesson (iii) Guided practice (iv) individual practice (v) Monitoring and assessment.

3.4.7 Teachers’ Instructional Guide on Conventional Lecture Method (TIGCLM)

Here, students sit individually throughout the lesson. The treatment for each lesson is in form of lecture.

(i) The instructor presents the lesson in form of lecture

(ii) Students listen to the teacher and write down chalkboard summaries.

(iii) Students ask the teacher questions on areas of the topic that is not clear to them.

(iv) Students answer the teacher‘s questions individually.

(v) Students are given take home assignment.

The manual in form of lesson note was prepared by the researcher and sup-plied to the instructors.