Statistics Assignment 4

Homework 4

Directions: Homework 4 is divided into two parts. Part 1 asks you to interpret a graph while Part 2 asks you to conduct item analyses. See Parts 1 and 2 below for details.

Part 1: Interpreting a Graph:

This is a bar graph (see Figure 1 below) of Grade 3 reading achievement separated into two components (fluency and comprehension) as well as their total score, for Lake Forest School and its district for each of 3 years.

Figure 1: Grade 3 Reading Achievement Scores Over Three Years

Suppose Lake Forest School had started using a new reading program at the beginning of the 2004–05 school year while the rest of the district continued with the old program. The annual reading achievement test is given toward the end of academic year.

1. Looking at this data, what are your thoughts about the new curriculum?

2. Which of these statements would you agree with and why?

a. Lake Forest School has not benefited from the new reading program since it was first implemented in 2004–2005.

b. Compared to the old program, the new reading program appeared to help students with their reading comprehension skills.

c. Scores move around from year to year, but the new reading program appears promising for enhancing students’ reading fluency.

Part 2: Item Analyses

Twelve students have taken an objective assessment. The quiz contained 10 questions. In Table 1 below, the students’ scores have been listed from high to low. There are four students in the upper half (Bob, Julie, Terrance, Virginia) and four students in the lower half (Nora, Jane, Natalie, Kate). The number “1” indicates a correct answer on the question; “0” indicates an incorrect answer. The total score represents the percentage correct.

Table 1

Note: An EXCEL file of the Table 1 data has been (attached).

Complete the Item Analysis Chart below (3 points):

Item Analysis
	# Correct (upper group)	# Correct (Lower Group)	Item difficulty (p)	Item Discrimination (D)
Question 1
Question 2
Question 3
Question 4
Question 5
Question 6
Question 7
Question 8
Question 9
Question 10

Once you have completed the Item Analysis Chart answer the following questions:

1. Which question was the easiest? Explain why.

2. Which question was the most difficult? Explain why.

3. Which item has the poorest discrimination? Explain why.

4. Which questions would you eliminate first (if any)? Explain why.

12345678910

Bob1001111111111

Julie901011111111

Terrance900111111111

Virginia801110110111

Sally700110110111

Preston700011111110

Sandy701011110110

David601001110101

Nora501110110000

Jane500010111100

Natalie401110001000

Kate300100010010

Total

Score (%)

Questions Student

Name