View in EDS

Question Format Is the Best Predictor of Item Discrimination: A Multivariable Analysis

Saved in:
Bibliographic Details
Title: Question Format Is the Best Predictor of Item Discrimination: A Multivariable Analysis
Language: English
Authors: Kirk Hillsley (ORCID 0009-0005-2965-132X)
Source: Journal of Microbiology & Biology Education. 2025 26(3).
Availability: American Society for Microbiology. 1752 N Street NW, Washington, DC 20036. Tel: 202-737-3600; e-mail: journals@asmusa.org; Web site: https://journals.asm.org/journal/jmbe
Peer Reviewed: Y
Page Count: 12
Publication Date: 2025
Document Type: Journal Articles
Reports - Research
Education Level: Higher Education
Postsecondary Education
Descriptors: Test Items, Test Format, Biology, Science Tests, Scores, Undergraduate Study, Foreign Countries, Difficulty Level, Item Banks
Geographic Terms: Canada
ISSN: 1935-7877
1935-7885
Abstract: Item discrimination, the point-biserial correlation between performance on a question and total exam score, was analyzed in relation to question format, difficulty, and Bloom's taxonomy, which are rarely studied together in a joint framework. To estimate their independent contributions in undergraduate biology examinations, simultaneous multivariable linear and logistic models were conducted on an upper year biology item bank (n = 754). Predictors were question format (multiple-choice question [MCQ], short answer [SA], true/false [TF]), difficulty (easy >80%, moderate 60%-80%, hard <60%), and Bloom (recall, understanding, application, analysis). Question format was the strongest independent predictor. Relative to MCQs, SA items showed higher discrimination and greater odds of meeting the ≥0.35 threshold (odds ratio [OR] = 4.18), while TF items were less discriminating (OR = 0.58). Moderate and hard items exceeded easy questions (ORs = 2.75 and 2.45, respectively). For Bloom, higher-order items outperformed recall questions overall; both understanding and analysis items discriminated better than recall items (ORs = 1.4 and 3.56, respectively). A post hoc grouping of moderate difficulty questions showed that SA + higher-order items (0.53) exceeded MCQ + recall items (0.35), with 89% vs 53% of these items, respectively, meeting a discrimination threshold of ≥0.35. In simultaneous models, question format was the strongest independent predictor of item discrimination, moderate difficulty optimized discrimination, and higher-order objectives exceeded recall. These results provide exploratory insights from a single-institution case study and suggest that adding some higher-order short-answer questions of moderate difficulty may represent a pragmatic strategy for improving assessment quality.
Abstractor: As Provided
Entry Date: 2026
Accession Number: EJ1504782
Database: ERIC
FullText Text:
  Availability: 0
CustomLinks:
  – Url: https://eric.ed.gov/contentdelivery/servlet/ERICServlet?accno=EJ1504782
    Name: ERIC Full Text
    Category: fullText
    Text: Full Text from ERIC
Header DbId: eric
DbLabel: ERIC
An: EJ1504782
AccessLevel: 3
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Question Format Is the Best Predictor of Item Discrimination: A Multivariable Analysis
– Name: Language
  Label: Language
  Group: Lang
  Data: English
– Name: Author
  Label: Authors
  Group: Au
  Data: &lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Kirk+Hillsley%22&quot;&gt;Kirk Hillsley&lt;/searchLink&gt; (ORCID &lt;externalLink term=&quot;http://orcid.org/0009-0005-2965-132X&quot;&gt;0009-0005-2965-132X&lt;/externalLink&gt;)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: &lt;searchLink fieldCode=&quot;SO&quot; term=&quot;%22Journal+of+Microbiology+%26+Biology+Education%22&quot;&gt;&lt;i&gt;Journal of Microbiology &amp; Biology Education&lt;/i&gt;&lt;/searchLink&gt;. 2025 26(3).
– Name: Avail
  Label: Availability
  Group: Avail
  Data: American Society for Microbiology. 1752 N Street NW, Washington, DC 20036. Tel: 202-737-3600; e-mail: journals@asmusa.org; Web site: https://journals.asm.org/journal/jmbe
– Name: PeerReviewed
  Label: Peer Reviewed
  Group: SrcInfo
  Data: Y
– Name: Pages
  Label: Page Count
  Group: Src
  Data: 12
– Name: DatePubCY
  Label: Publication Date
  Group: Date
  Data: 2025
– Name: TypeDocument
  Label: Document Type
  Group: TypDoc
  Data: Journal Articles&lt;br /&gt;Reports - Research
– Name: Audience
  Label: Education Level
  Group: Audnce
  Data: &lt;searchLink fieldCode=&quot;EL&quot; term=&quot;%22Higher+Education%22&quot;&gt;Higher Education&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;EL&quot; term=&quot;%22Postsecondary+Education%22&quot;&gt;Postsecondary Education&lt;/searchLink&gt;
– Name: Subject
  Label: Descriptors
  Group: Su
  Data: &lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Test+Items%22&quot;&gt;Test Items&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Test+Format%22&quot;&gt;Test Format&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Biology%22&quot;&gt;Biology&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Science+Tests%22&quot;&gt;Science Tests&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Scores%22&quot;&gt;Scores&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Undergraduate+Study%22&quot;&gt;Undergraduate Study&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Foreign+Countries%22&quot;&gt;Foreign Countries&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Difficulty+Level%22&quot;&gt;Difficulty Level&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Item+Banks%22&quot;&gt;Item Banks&lt;/searchLink&gt;
– Name: Subject
  Label: Geographic Terms
  Group: Su
  Data: &lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Canada%22&quot;&gt;Canada&lt;/searchLink&gt;
– Name: ISSN
  Label: ISSN
  Group: ISSN
  Data: 1935-7877&lt;br /&gt;1935-7885
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Item discrimination, the point-biserial correlation between performance on a question and total exam score, was analyzed in relation to question format, difficulty, and Bloom&#39;s taxonomy, which are rarely studied together in a joint framework. To estimate their independent contributions in undergraduate biology examinations, simultaneous multivariable linear and logistic models were conducted on an upper year biology item bank (n = 754). Predictors were question format (multiple-choice question [MCQ], short answer [SA], true/false [TF]), difficulty (easy &gt;80%, moderate 60%-80%, hard &lt;60%), and Bloom (recall, understanding, application, analysis). Question format was the strongest independent predictor. Relative to MCQs, SA items showed higher discrimination and greater odds of meeting the ≥0.35 threshold (odds ratio [OR] = 4.18), while TF items were less discriminating (OR = 0.58). Moderate and hard items exceeded easy questions (ORs = 2.75 and 2.45, respectively). For Bloom, higher-order items outperformed recall questions overall; both understanding and analysis items discriminated better than recall items (ORs = 1.4 and 3.56, respectively). A post hoc grouping of moderate difficulty questions showed that SA + higher-order items (0.53) exceeded MCQ + recall items (0.35), with 89% vs 53% of these items, respectively, meeting a discrimination threshold of ≥0.35. In simultaneous models, question format was the strongest independent predictor of item discrimination, moderate difficulty optimized discrimination, and higher-order objectives exceeded recall. These results provide exploratory insights from a single-institution case study and suggest that adding some higher-order short-answer questions of moderate difficulty may represent a pragmatic strategy for improving assessment quality.
– Name: AbstractInfo
  Label: Abstractor
  Group: Ab
  Data: As Provided
– Name: DateEntry
  Label: Entry Date
  Group: Date
  Data: 2026
– Name: AN
  Label: Accession Number
  Group: ID
  Data: EJ1504782
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=eric&AN=EJ1504782
RecordInfo BibRecord:
  BibEntity:
    Languages:
      – Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 12
    Subjects:
      – SubjectFull: Test Items
        Type: general
      – SubjectFull: Test Format
        Type: general
      – SubjectFull: Biology
        Type: general
      – SubjectFull: Science Tests
        Type: general
      – SubjectFull: Scores
        Type: general
      – SubjectFull: Undergraduate Study
        Type: general
      – SubjectFull: Foreign Countries
        Type: general
      – SubjectFull: Difficulty Level
        Type: general
      – SubjectFull: Item Banks
        Type: general
      – SubjectFull: Canada
        Type: general
    Titles:
      – TitleFull: Question Format Is the Best Predictor of Item Discrimination: A Multivariable Analysis
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Kirk Hillsley
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 12
              Type: published
              Y: 2025
          Identifiers:
            – Type: issn-print
              Value: 1935-7877
            – Type: issn-electronic
              Value: 1935-7885
          Numbering:
            – Type: volume
              Value: 26
            – Type: issue
              Value: 3
          Titles:
            – TitleFull: Journal of Microbiology & Biology Education
              Type: main
ResultId 1