The following instruments were used for the study.
i. Biology Achievement Test (BAT)
ii. Questionnaire on Attitude to Biology (QAB) iii. Biology Practical Skills Rating Scale (BPSRS)
iv. Instructional Guide on Experiential Learning Strategy (IGELS) v. Instructional Guide on Generative Learning Strategy (IGGLS) vi. Instructional Guide on Modified Conventional Strategy (IGMCS) vii. Mental Ability Test (MAT)
viii. Evaluation Sheet for Assessing Teachers (ESAT) 3.4.1 Biology Achievement Test (BAT) and its Validation
BAT was designed to measure students‘ performance in specific academic areas in Biology. The instrument as shown in appendix I was in two sections - A and B. Section A has to do with the personal data of the respondents while section B elicited response from the students. The test was made up of forty five items that covered topics in the senior secondary school syllabus, particularly the concepts examined. Forty five items were reduced to thirty six by educational experts and experts in the field of science education, while validation after trial – testing reduced it to twenty five. The table of specification for SBAT is shown Table 3.2
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Table 3.2: Table of specification for BAT Topic/
Concept
Knowledge Compreh ension
Appli cation
Analy sis
Synthe sis
Evaluatio n
Total Pollution 2(1,9) 2(2,4) 2(3,5) 2(11,1
3)
1(8) 2(6,7) 11
Ecology - 1(16) 1(10) - - 1(12) 3
Conservation of natural resources
2(17,21) 1(18) 1(19) - 1(15) 1(14) 6
Population 1(25) 2(20,23) 1(24) 1(22) - - 5
Total 5 6 5 3 2 4 25
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Forty five items – multiple choice objective test was scrutinized by the researcher‘s supervisor, teachers, and educational experts for content validity. The items were then reduced to thirty six. The instrument with the thirty six items was trial-tested on thirty students outside the study area, making use of discimation indices of 0.4-0.6. The items that ranked below 0.4 represented those that were too cheap while those above 0.6 were those that were too difficult. Based on this difficulty level, the surviving items were twenty – five as shown in the Table 3.2.
Kuder – Richardson formula 20 was used to calculate the reliability of the test.
The value obtained was 0.74.
3.4.2 Questionnaire on Attitude to Biology (QAB) and its Validation
QAB is an attitudinal questionnaire developed by the researcher and aimed at assessing students‘ attitude to biology. The instrument was divided into two sections- A and B and was presented in appendixes IIA and IIB. Section A contained the personal data of the respondent while section B contained twenty-seven open ended items. Each item wss placed on a four point Likert type ordinal scale of Strongly Agree (SA), Agree (A), Disagree (D) and Strongly Disagree (SD). The scoring was from 4, 3, 2, to 1 for positively worded items and 1, 2, 3 to 4 for negatively worded questions. The number of the items was reduced later after trial-testing; validation reduced it to twenty.
For face and content validity, the instrument containing twenty seven items initially was given to experts in Biology education and more particularly Biology teachers. Copies were also given to English teachers and finally my supervisor so as to make necessary correction and ascertain its effectiveness for the study. After the expert assessment, some items were removed while some were modified. This assessment exercise reduced the items to twenty five which were used for trial-testing on thirty students in a pilot school. After validation, the items were eventually reduced to twenty. Crombach alpha co-efficient of 0.82 was obtained.
Therefore, the instrument was considered valid enough to be used for the study.
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3.4.3 Biology Practical Skills Rating Scale (BPSRS) and its Validation
The Biology Practical Skills Rating Scale (BPSRS) was designed to access students‘ practical task based on direct observation during their laboratory work.
The Biology Practical Skills Rating Scale (BPSRS) was used to determine students‘ ability to manipulate, observe, record, label, classify and draw in the practical class. A copy of the instrument was shown in appendix III.
This instrument was in two sections – A and B. Section A has to do with the personal data of the respondents while section B rated the students‘ practical skills in Biology. The skills rated were: observation, recording, labeling, drawing, classification and manipulation.
Section B was a six-point continuum that ranged from zero for total inability to exhibit the skills, to five at the extreme for full exhibition of the skills.
The instrument was used and scored by three independent raters and the inter-rater reliability was estimated using Scott п. The inter-rater reliability index obtained was 0.75.
3.4.4 Instructional Guide on Experiential Learning Strategy (IGELS) and its Validation.
The instructional guide was adopted from Kolb‘s (1984) experiential learning model and was used for the teaching of treatment group one. Learners worked in groups of five. In the guide, there was information to the teacher who was one of the research assistants. The instructional guide provided an opportunity for the learners to play active roles and be at the centre of the learning process.
There were four procedural steps which include: