Diagnostic assessment
A diagnostic assessment is a check of what a learner already knows, and where the gaps are, before teaching or studying begins. It is usually low-stakes and ungraded, and its job is to decide where to start and what to focus on, not to give a mark.
In more detail
It answers one question: where do I start? A teacher uses a pretest to see which parts of a unit students already know, and a student can take a practice test before revising to find weak topics. Common forms are pretests, placement tests, concept inventories, short quizzes, KWL charts and reading or math screeners.
It sits at the start of the sequence. Diagnostic assessment comes before learning, formative assessment during it and summative assessment at the end. The tools overlap: the same quiz is diagnostic on day one and formative on day ten. The word also has a clinical use for identifying learning difficulties, which is a separate, specialist process.
A diagnostic only helps if it changes the plan. If the results go in a drawer, the benefit is lost. Keep it low-stakes, so people answer honestly and show their real gaps. A pretest can feel hard, and that is fine: even wrong guesses can improve later learning, an effect covered under pretesting.
Diagnostic, formative and summative assessment compared
| Type | When | Purpose | Stakes |
|---|---|---|---|
| Diagnostic | Before learning | Find the starting point and the gaps | Low or none |
| Formative | During learning | Adjust teaching and studying | Low |
| Summative | After learning | Judge what was learned | High, graded |
Example
Before a statistics unit, Mr. Okafor gives a 10-question pretest on averages, percentages and graphs. Seven students miss every percentage question. He spends the first lesson on percentages and skips the graph recap that everyone passed. A student working alone can do the same with a 15-question quiz on a chapter before reading it, then read the sections behind the missed questions first.
How to use it
- 1
Decide which skills or concepts the next unit rests on.
- 2
Write or pick 10 to 20 questions that cover them, easy and hard mixed.
- 3
Take it before you study, closed book, and treat it as ungraded.
- 4
Sort the results by topic, not by total score, to find clusters of gaps.
- 5
Plan the first sessions around the weakest topics and test again after a week.
How StudyPDF does this
StudyPDF works this way for your own course. Make a quiz or a practice exam from your material before you start revising, and the per-concept results show your weakest topics first. A placement check can calibrate your study plan before the first session, and the plan gives weak concepts earlier and repeated sessions.
See also
Common questions
What is an example of a diagnostic assessment?
A 10-question pretest at the start of a unit, a placement test for a language course, or a short quiz on the skills a new topic needs. It is not graded, and the results decide where teaching or studying starts.
What is the difference between diagnostic and formative assessment?
Timing and purpose. Diagnostic assessment comes before instruction to find the starting point, formative assessment happens during learning to adjust it. The same quiz can be either, depending on when you use it.
Put it to work on your own course
Upload your lectures and ask Bo. Cited answers, plus flashcards, exams, and more built from your material.