jMetrik Quick Start

7/29/2019 jMetrik Quick Start

http://slidepdf.com/reader/full/jmetrik-quick-start 1/10

Quick Start Guide

(Images updated November 2, 2011)

Select a link below to jump to a different section. If you have any questions after reading the Quick Start Guide, please send

an email to [email protected].

Importing Data

Viewing Variable Information

Scoring Item Responses

Specifying Multiple Correct Answers and Collapsing Categories

Handling Missing Data

After installing jMetrik, you will need to create a new project and import data. These tasks are handled through the "Manage"

menu. For now, you will use the default workspace. To create a project in the default workspace, select "Default" in the

Workspace Tree (see image below).

Select "New Project" in the "Manage" menu.

Home Features Screenshots Download Help Services

trik http://www.itemanalysis.com/quick-start-guide.php

10 17/09/2012 9:44



Type a name for your project in the "Create New Project" dialog box. The name should not contain any spaces or special

characters. Click the "Create" button to create the project. A project is essentially a database. This action creates a new

database that can contain many data tables.

To import data into a project, select the project and then click "Import Data" in the "Manage" menu.


10 17/09/2012 9:44



Use the Import Data dialog box "Browse" button to view a file selection dialog box.

The file selection dialog box allows you to navigate to your file and select it. Only plain text delimited files are accepted for

import. After selecting the file to import, choose the type of delimiter and specify whether or not variables names are

included in the first row of your file. Click "Browse" to confirm your selection.


10 17/09/2012 9:44



You must type a name in the "Data Name" text box. jMetrik will not automatically choose a name for you. Data names must

be unique. You can not have two files with the same data name. In the example below, the data name is fall2009.

After clicking "Import," you will recevie confirmation of a successful import. You can save or cancel this confirmation. Look

closely at the image below. There is a small + sign next to the project name. If you click this + sign, you will expand the

Workspace Tree. The imported data file name is now visible. If you click on the file name "FALL2009" you will see a view of

the data.


10 17/09/2012 9:44



You can scroll through the data to visually verify that data have been imported correctly. jMetrik only provides a view of the

data at the moment. Data entry and editing features will be added to jMetrik in the future. Notice that the selected project

and data file are displayed in the jMetrik status bar at teh bottom of the program. The currently selected data are active.

"Analyze" and "Graph" menu options apply to the active data file.

Viewing VariableInformation

In addition to providing a view of the data, jMetrik provides a view of variable information. If you click on the "Variables" tab

at the bottom of the program, you will see information about each variable (see image below). Variable names are displayed

in the first column. You can not edit variable names. The remaining columns display editable information: Type, Scoring,

Group, and Label.

Four item types are defined in jMetrik: Not Item, Binary Item, Polytomous Item, and Continuous Item. "Not Item" is the

default. Any variable in the data that is not a test item should be a "Not Item." For example, a variable that defines each

examinee's gender is a "Not Item." A binary item has only two score categories: 0 and 1. A polytomous item has multiple

score categories such as 0, 1, 2, and 3. Scoring must be defined for binary and polytomous items. A continuous item takes on


10 17/09/2012 9:44



values of the original variable. (Note: Continuous items are defined specifically for the Confirmatory Factor Analysis option.

Item and DIF anlaysis options only apply to binary or polytomous items.)

Although the "Type" column is shown before the "Scoring" column, you do not need to specify the type first. jMetr ik will

automatically update the "Type" column according to the information you provide in the "Scoring" column. The only time you

need to directly edit the "Type" column is when you have a Continuous Item. If you click on a cell in the "Scoring" column,

you will see the Option Scoring dialog that is explained below.

The "Group" column allows you to identify item groups. Item groups may represent testlets (subset of related items), items

that share a response scale (binary items, polytomous items), subscales, or any user defined partition of the test items. Item

groups affect the analysis options in a number of ways. For example, an item analysis will provide reliability statistics for

item group defined part tests. If you define two item groups and each has the same number of items, the item analysis will

provide split-half reliability estimates.

When item response theory is added, the "Group" column defines items that share a common rating scale. An Andrich rating

scale model is applied to all items in a group. A partial credit model is applied to items that are in their own group (i.e. an

item group with a single item).

When confirmatory factor analysis models are fully implemented in jMetrik, the "Group" column defines the way each item

corresponds to a factor in bifactor and simple structure models.

Finally, the "Label" column allows you to specify a descriptive label for each item. This functionality is not yet implemented.

It will be added in the future.

Scoring Item Responses

To conduct an item analysis, DIF analysis, confirmatory factor anlaysis, or nonparametric IRT analysis, you must specify the

scoring for each item. Click on a cell in the "Scoring" column to display the Option Scoring tool (see below).


10 17/09/2012 9:44



Note: The decimal places are added automatically once you click OK.

Enter all possible response otions in the first column and the score assigned to each option in the second column. Response

options are case sensitive meaning that the program views "p" and "P" as two different things. Be sure you use the case that

is used in your data file. Note that your data may be numbers or letters, but for many anlaysis options in jMetrik, the

program views your data as text. Therefore, you must specify the option scoring even when your data are numeric. In the

example below, the data contain letters.

Assign a numeric score value to each response option. jMetrik uses this value to compute overall test scores and numeric

summaries such as the overall item mean.

In the figure below, there are four possible response options: A, B, C, and D. Option A is the correct answer because it has a

score of one and everything else has a score of 0. Notice that the cursor has been moved to the row following the last entry.

You must move to the row after your last entry in the scoring tool in order for the program to accept yourvalues. If you do not, the last entry will default to a score of 0.

To replicate this item scoring for other i tems that have "A" as the correct answer, cl ick "Replicate."

The image below shows that items 9, 12, 15, and so on have been selected to share the same scoring as item 1. Click "Run"


10 17/09/2012 9:44



and then click "OK" on the Option Scoring dialog to complete the option scoring for all items that have "A" as the correct

answer.

The image below shows the result of the previous step. Contiue specifying the option scoring for every item in your test.

Specifying Multiple Correct Answers and Collapsing Categories

The Option Scoring tool is very flexible. A score value may be assigned to each possible resposne option. It often happens

that an i tem has two correct answers. Both correct answers can be specified in the Option Scoring Tool by awarding both

options a score of 1. The example below shows that options "A" and "C" are correct.


10 17/09/2012 9:44



Note: The decimal places are added automatically once you click OK.

Scoring must be specified for polytomous items too. The image below shows that the response options of 0, 1, 2, and 3 are

scored 0, 1, 2, and 3.

Different scores may be assigned to a polytomous item. For example, if your original response options are 1, 2, 3 and 4, you

can score them as 0, 1, 2, and 3.

Note: No decimal places here because OK has not been clicked.


10 17/09/2012 9:44



You can also collapse polytomous item categories. In the example below, option categories 2 and 3 have been collapsed. Both

response options are scored as a 2.

Note: No decimal places here because OK has not been clicked.

Handling Missing Data

You have several options for handling missing data. You can include a code in your data that represents a missing value. You

can then use the scoring tool to specify the score assigned to missing values. In the example below, the response option "M"

is included in teh data to represent missing data. This options is scored as 0 points.

A user defined missing data code give you the most control over how missing responses are scored. You are not required to

use this approach. You can simply leave missing data responses blank in your original data fi le. Missing data are handled

differently depending on the type of analysis you are running. Missing data operations are described for each option in the

"Analyze" menu.

Frequencies: Missing data tabulated in their own category. You will see a frequency provide for a blank entry.

Descritives: Cases with missing data are ignored item-by-item. Listwise deletion is not used for Descriptives. The valid

sample size reflects the number of cases with data.

Correlation: You have the option of using l istwise or pairwise deletion.

Item Analysis: Missing responses are scored as 0 points by default. You have the option of using li stwise deletion.

DIF Analysis: Missing item responses are scored as 0 points by default. Cases missing values for the DIF group variable

are deleted listwise.

Nonparametric Curves: Missing responses are scored as 0 points by default.

Confirmatory Factor Analysis: You have the option of using listwise or pairwise deletion.

Return to top

© 2007-2011 jMetrik.com/ItemAnalysis.com. All Rights Reserved.


jMetrik Quick Start

Documents

Transcript of jMetrik Quick Start