## Item Analysis

** – O**ne of the most important (if least appealing) tasks confronting faculty members is the evaluation of student performance. This task requires considerable skill, in part because it presents so many choices. Decisions must be made concerning the method, format, timing, and duration of the evaluative procedures.

##### – Once designed, the evaluative procedure must be administered and then scored, interpreted, and graded. Afterwards, feedback must be presented to students. Accomplishing these tasks demands a broad range of cognitive, technical, and interpersonal resources on the part of faculty. But an even more critical task remains, one that perhaps too few faculty undertake with sufficient skill and tenacity: investigating the **quality** of the evaluative procedure.

## Item Analysis Procedure

**Score each answer sheet**, write score total on the corner- Sort the pile into
**rank order**from highest to lowest score - Take ‘top’ pile,
**count number of students**who responded to**each alternative**take top 27% (27 out of 100); bottom 27% (so only dealing with 54, not all 100) - Count the number of students in the top or upper and lower groups
- record the frequency

**ITEM ANALYSIS FORM TEACHER CONSTRUCTED TESTS**`ITEM UPPER LOWER DIFFERENCE D TOTAL DIFFICULTY 1. A`

**0***B**4**C**1**D**1**O - estimate the index of difficulty using the formula: P= (RU+RL)/N

where

P = difficulty index

RU = right response of upper group

RL = right response of lower group

**Interpretation of Difficulty Index**

Very easy ——— 0.91-0.95

easy ——— 0.76-0.90

average ——— 0.25-0.75

difficult ——— 0.10-0.24

Very difficult ——— 0.05-0.09

difficulty of whole test

Pwt = Ʃp/N

7. Estimate item discrimination power by using the formula: D=(RU-RL)/Ng

where

RU = right response of upper group

RL = right response of lower group

N = number of student in each group

**Interpretation of Discrimination Index**

0.40 and up – Very Discriminating Items

0.300 – 0.39 – Discriminating Items

0.20 – 0.29 – Reasonably Discriminating Items

0.10 – 0.19 – Marginally Discriminating Items; subject to improvement

Below 0.10 – Unproductive Items, to be rejected

__Difficulty of the Whole Test__

Dwt = Ʃ D / N

8. Determine the effectiveness of the distracters

9. Determine the Item Category

Good – high discrimination index (0.40 and up) average difficulty (0.26-0.75)

Fair – discrimination index (0.20-0.39) somewhat high or low difficulty index (0.80 or higher, 0.20 or lower); also discriminating index (0.16 to 0.19 but for revision)

Poor – very low discriminating index (below (0.16); extreme difficulty index, either too easy 0.80 and above or too difficult (0.20 and below)