Item Response Formats 101. Three classes of items will be used to assess the competencies and scientific knowledge
identified in the framework. About one-third of the items will be in each of the three classes:
Simple multiple-choice: Items calling for
selection of a single response from four options
selection of a “hot spot,” an answer that is a selectable element within a graphic or text.
Complex multiple-choice : Items calling for
responses to a series of related “Yes/No” questions that are treated for scoring as a single
item (the typical format in 2006)
selection of more than one response from a list
completion of a sentence by selecting drop-down choices to fill multiple blanks
“drag-and-drop” responses, allowing students to move elements on screen to complete a
task of matching, ordering, or categorising.
Constructed response : Items calling for written or drawn responses.
Constructed response items in scientific literacy typically call for a written responses
ranging from a phrase to a short paragraph (
e.g. , two to four sentences of explanation). A
small number of constructed response items call for drawing (
e.g. , of a graph or diagram).
For computer delivery, any such items will be supported by simple drawing editors that are
specific to the response required.
102. Also, in 2015, some responses will be captured by interactive tasks, for example, a student’s
choices for manipulating variables in a simulated scientific enquiry. Responses to these interactive
tasks will likely be scored as complex multiple choice items. Some kinds of responses to interactive
tasks may be sufficiently open-ended that they will be treated as constructed response.
Assessment Structure 103. For PISA 2015, computer-based assessment will be the primary mode of delivery for all
domains, including scientific literacy. All new science literacy items will only be available in the
computer-based assessment. However a paper-based assessment instrument will be provided for
countries choosing not to test their students by computer which will consist only of the trend items.
104. Scientific literacy items will be organised into 30-
minute sections called “clusters.” Each
cluster will include either only new units or only trend units. Overall for 2015, the target number of
clusters to be included in the main survey is: