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Questions and Answers
What does item discrimination measure?
Which group in item discrimination possesses the target ability?
What is another name for the upper group in the context of item discrimination?
How does item discrimination compare performance?
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Who are referred to as Non-Masters in item discrimination?
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Which statement best describes the essence of item discrimination?
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What term is used to describe individuals in the upper region of test scores?
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Item discrimination is an estimate that compares item performance with which aspects?
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Which group is most likely to answer an item correctly if it has high discrimination?
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What distinguishes high scorers from low scorers in the context of item discrimination?
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What does a higher item discrimination index indicate?
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What minimum value should the item discrimination index have?
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Which aspect of item performance is measured by the item discrimination index?
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How does the item discrimination index (d) affect the reliability of a test?
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Which of the following indicates an adequately discriminating item?
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What does an item difficulty index of 0.20 indicate?
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Which of the following statements accurately describes the item difficulty (p)?
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If an item on a test is answered correctly by 70% of the test takers, what is its difficulty index?
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How should item difficulty (p) be interpreted when designing a test?
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What does a high item difficulty index indicate about a test item?
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What does an item difficulty index measure?
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Which item difficulty index indicates a well-balanced item?
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What does an item difficulty index lower than 0.30 signify?
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How is the difficulty of an item related to the item difficulty index?
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What should be the ideal range for item difficulty index?
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What is the main objective of using participants' responses in test items during factor analysis?
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In the context of factor analysis, what does a higher loading for a test item indicate?
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Which of the following is NOT true about constructs in factor analysis?
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What does each item’s contribution to the overall score of the factor indicate in factor analysis?
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What does the diagram in the provided image primarily illustrate?
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What does a factor loading represent in the context of item validity?
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What is the minimum acceptable value for a standardized factor loading or indicator loading?
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What should be done with indicators that do not meet the minimum standardized factor loading criteria?
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Why are factor loadings important in the context of item validity?
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What does the item-validity index provide an indication of?
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What is the primary purpose of the item-validity index?
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Which of the following best describes the item-validity index?
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In the context of educational assessments, what does the item-validity index help to evaluate?
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Which term is defined as a statistic designed to measure the extent to which a test measures what it claims to measure?
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What is the purpose of performing an item-total/item-rest correlation test?
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What does a correlation value less than 0.2 or 0.3 indicate in the context of item-total/item-rest correlation?
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Which statistic is used in item-total/item-rest correlation to evaluate item consistency?
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What is checked by item-total/item-rest correlation in the context of test items?
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Who developed the guideline that a correlation value less than 0.2 or 0.3 indicates poor correlation?
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Study Notes
Item Validity
- Item validity index measures how well a test measures what it claims to measure
Item Discrimination (d)
- High item discrimination index: item is easy for upper group and difficult for lower group
- Low item discrimination index: both groups answer correctly
- Negative item discrimination index: item is difficult for upper group and easy for lower group
- Item discrimination index indicates how well an item separates high scorers from low scorers
- Higher the d, more high scorers answer the item correctly
- Item discrimination index should be at least 0.30
Basics of Factor Analysis
- Constructs are not directly observable, but can be quantified through test items
- Factor analysis model: latent variable connected to observed variables through loadings
- Higher the loading, stronger the relationship between observed variable and latent variable
Item Reliability
- Item-total/item-rest correlation test checks if an item is inconsistent with others
- Correlation value less than 0.2 or 0.3 indicates poor correlation
Item Difficulty (p)
- Item difficulty index measures the proportion of examinees who answered correctly
- Higher the difficulty, the easier the item
- Item difficulty index should range from 0.30 to 0.70
- Higher than 0.70: too easy, lower than 0.30: too difficult
- Item difficulty (p) is also known as the item easiness index
Item Validity Using Factor Analysis
- Factor loadings represent the relationship between the item and the variable being measured
- Standardized factor loading/indicator loading should be at least 0.50
- Indicators not meeting this criterion may be removed
Item Discrimination (d)
- Measures how well an individual test item distinguishes between high and low scorers on the entire test
- High 'd' values indicate that a large proportion of high scorers (masters) answer the item correctly
- The item discrimination index should have a minimum value of at least 0.30
Item Difficulty (p)
- Item difficulty (p) is a measure of how well test takers perform on a particular item (question) on a test.
- It's calculated as the proportion of test takers who answered the item correctly.
- For instance, if 84% of test takers answered item number 1 correctly, the item difficulty (p) would be 0.84.
- Note that this definition actually measures the easiness of the item rather than its difficulty, so it's more accurate to think of item difficulty (p) as the item easiness index.
Item Difficulty (p)
- Item difficulty (p) measures the proportion of examinees who answered the item correctly.
- Higher difficulty values indicate easier items.
- The ideal range for item difficulty index is between 0.30 and 0.70.
- Items with a difficulty index above 0.70 are considered too easy.
- Items with a difficulty index below 0.30 are considered too difficult.
Factor Analysis Basics
- Constructs are abstract and cannot be directly observed.
- Researchers believe that participants' responses to test items can help quantify the construct being measured.
Factor Analysis Diagram
- A factor or construct is represented by a diagram, showing its relationship with individual test items (e.g., SWL1 to SWL5).
- Each test item has a loading, indicating its relationship strength with the factor.
- A higher loading indicates a closer relationship between the item and the factor.
- Each item contributes to the overall score of the factor, in this case, SWL.
Factor Analysis for Item Validity
- Factor loadings (λ) are used to measure the relationship between an item and the variable being measured, as referenced in Hair et al. (1987, 2009) and Kock (2015)
- The standardized factor loading/indicator loading should be at least 0.50
- Items that do not meet this criteria may be removed
Factor Analysis for Item Validity
- Factor loadings (λ) are used to measure the relationship between an item and the variable being measured, as referenced in Hair et al. (1987, 2009) and Kock (2015)
- The standardized factor loading/indicator loading should be at least 0.50
- Items that do not meet this criteria may be removed
Item Discrimination (d)
- Measures how adequately an item separates high scorers from low scorers on the entire test
- A high item discrimination index indicates that the item is easy for the upper group and difficult for the lower group
- A low item discrimination index indicates that both the lower group and the upper group are getting the correct answer to the item
- A negative item discrimination index indicates that the item is difficult for the upper group but easy for the lower group
- The item-discrimination index should be at least 0.30
Item Difficulty (p)
- Measures the proportion of examinees who answered the item correctly
- Higher difficulty index indicates an easier item
- Item difficulty index should range from 0.30 to 0.70
- Indices higher than 0.70 are too easy, and those lower than 0.30 are too difficult
- Example: if 84% of test takers answered an item correctly, the difficulty index is 0.84
Basics of Factor Analysis
- Constructs are not directly observable, but participants' responses to test items can quantify the construct
- Factor analysis model shows the relationship between observed variables and a latent variable
Item Validity Using Factor Analysis
- Factor loadings (λ) represent the relationship between the item and the variable being measured
- Standardized Factor loading/Indicator Loading should be at least 0.50
- Indicators that do not meet this criteria may be removed
Item Validity
- Item-validity index indicates the degree to which a test measures what it purports to measure
Item Reliability
- Item-total/item-rest correlation test checks if an item is inconsistent with other items
- Correlation values less than 0.2 or 0.3 indicate that the item does not correlate well with others
Item Reliability
- Item-total/item-rest correlation test is used to identify inconsistent items
- Correlation value less than 0.2 or 0.3 indicates poor correlation between an item and the other items (Field, 2009)
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Description
Item Reliability, Item Validity, Item Discrimination
