Diagnostic Assessment in Education: 3 Examples from a Teacher

Young students utilizing diagnostic assessment tools in the classroom sitting at a desk with a computer.

For educators, knowing where a student is in terms of skills and abilities is critical. It is challenging to move forward in a lesson or unit if the teacher doesn’t have a clear understanding of what a student can and cannot do. This is why diagnostic assessments tools such as pretesting, formative assessments, and other diagnostic assessments important. These tools allow educators to curate individualized lessons that meet students where they are rather than teaching without a clear focus on student ability.

Creating diagnostic tools and assessments can be time-consuming, however, using technology and online testing platforms can make the process more efficient. This allows educators to quickly determine a student’s level and begin planning impactful lessons right away. Within diagnostic testing, there are many different diagnostic assessment formats that educators may utilize to improve student learning and growth.

What are Diagnostic Assessments? 

In education, diagnostic assessments are evaluations to identify students’ strengths, weaknesses, knowledge gaps, and learning needs. These assessments are designed to inform educators about students’ current levels of understanding and to guide instructional planning. The primary goal is to diagnose specific areas where students may need additional support or intervention. 

Some common types of diagnostic assessments in education include:


  • Purpose: Conducted before a new unit or course to gauge students’ prior knowledge and skills.
  • Examples: Pre-tests, concept mapping, and K-W-L (Know, Want to know, Learned) charts.

Reading Diagnostic Assessment:

  • Purpose: Identify reading difficulties, literacy levels, and specific areas of weakness in reading.
  • Examples: Phonics assessments, fluency assessments, reading comprehension assessments, and decoding assessments.

Math Diagnostic Assessment:

  • Purpose: Assess mathematical understanding, identify gaps in knowledge, and pinpoint specific areas of difficulty.
  • Examples: Math fluency assessments, problem-solving assessments, and concept-specific assessments.

Writing Diagnostic Assessment:

  • Purpose: Evaluate students’ writing skills, including mechanics, organization, and expression.
  • Examples: Writing samples, essays, and rubrics assessing writing conventions.

Science and Social Studies Diagnostic Assessment:

  • Purpose: Assess understanding of key concepts in science and social studies.
  • Examples: Concept maps, content-specific quizzes, and project-based assessments.

English Language Learners (ELL) Diagnostic Assessment:

  • Purpose: Evaluate language proficiency and identify areas of need for English language learners.
  • Examples: Language proficiency assessments, oral interviews, and language development portfolios.

Special Education Diagnostic Assessment:

  • Purpose: Assess students with special needs to identify learning disabilities or challenges.
  • Examples: Psycho-educational assessments, individualized educational plan (IEP) evaluations, and adaptive behavior assessments.

The results of diagnostic assessment tools are valuable for teachers to tailor their instruction to meet individual student needs. These assessments provide insights into instructional adjustments, the development of targeted interventions, and the creation of differentiated learning experiences. They may also help to promote a more personalized and responsive approach to teaching, fostering student growth and academic success.

Differences Between Formative and Summative Testing 

Formative and summative assessments are two distinct types of assessments used in education, each serving different purposes in the learning and evaluation process. The summative assessment formats tend to be more traditional and may include end-of-unit or year tests, essays, or projects, whereas formative assessments are ongoing, smaller in size, and may provide immediate feedback. Generally speaking, formative assessment formats allow teachers to see what students know and change instruction accordingly. Summative assessments are designed to tell a teacher what a student has learned after all instruction has occurred. 

Formative and summative assessments differ not only in their purposes and timing but also in their testing formats. The formats of these assessments are designed to align with their respective goals and the stage of the learning process. 

Here are key differences in the assessment formats of formative and summative assessments:

Formative Assessment  Summative Assessment
Informal and Varied: They can include classroom discussions, quizzes, polls, exit tickets, short written reflections, observations, and peer reviews. Standardized and Structured: They aim to provide a comprehensive and consistent evaluation of students’ overall performance at the end of a unit, course, or academic period.
Low-Stakes: Typically low-stakes in nature. The emphasis is on providing constructive feedback to guide learning rather than assigning grades. The goal is to identify and address learning gaps promptly. High-Stakes: Generally high-stakes, as they are used for making important decisions such as assigning grades, determining promotion, or evaluating program effectiveness.
Adaptable and Flexible: Formats are adaptable and flexible, allowing teachers to modify assessments based on the needs of individual students or the class as a whole.  Objective and Closed-Ended: This may involve objective and closed-ended formats, such as multiple-choice exams, standardized tests, essays, and long-answer questions. 
Qualitative Feedback: Teachers may provide comments, suggestions, or corrective guidance to help students understand and improve their understanding. Score-Based Feedback: While some written feedback may be provided, the primary focus is on summarizing and quantifying students’ performance.
Frequent and Ongoing: Because formative assessments are ongoing and frequent, they often involve quick checks for understanding integrated into daily instruction. Comprehensive Coverage: Covers a broad range of topics and learning objectives. The goal is to assess overall achievement and mastery of the content covered during the entire instructional period.
Peer and Self-Assessment: This may include opportunities for peer and self-assessment. Students may be involved in providing feedback to their peers or reflecting on their understanding and progress. External Evaluation: Often involves external evaluation, especially in the case of standardized tests. These assessments are designed to provide an impartial and standardized measure of student achievement.

Examples of Diagnostic Assessment Tools 

Diagnostic assessments may be used to assess students before learning is completed or before it has started altogether. Within the classroom, a teacher may implement and use these assessments in a variety of ways. Here are 3 real-world examples of diagnostic assessments and how they can be used to inform instruction: 

English Language Development (ELD) 

Schools have new students enrolled all of the time. In some cases, these students may speak a language other than English. In these cases, it is vitally important for the student to be placed correctly within an English Language Development classroom. To do this many school districts or states have a diagnostic screener test designed to accurately portray a student’s English skills and place them into ELD programming or not based on the results. 


A science teacher is teaching a new lesson on the human body, specifically the cardiovascular system. Rather than jumping right in and assuming students all are new to the material the teacher decides to provide students with a scenario in which a person begins to exercise. The teacher asks the students to describe what they think will happen to the person’s body as they exercise and why they think these changes occur. 

This small assessment can help the teacher gauge if students know that heart rate and breathing rate will increase, and if they know that this is done to increase oxygen levels in the muscles. Once the teacher has this information they can design lessons to meet the needs of their unique learners. 

Physical Education

In the physical education class, a teacher may have students with a wide range of abilities. For example, one student may be a star baseball player who can throw a ball with ease, while others may not know how to throw at all. As a diagnostic assessment, a teacher may ask students to pick up a ball and throw it at a target across the room. Through observational notes, or maybe even a video recording, the teacher can break down each student’s throw and designate the next steps. 

The main goal in developing diagnostic assessments is to ensure that students get what they need in terms of learning when they need it and that educators can identify and fill any gaps in learning that the student may have. Diagnostic assessment tools may be used differently depending on the class, some classes may use observation and student interviewing while other classes may use pretesting and journaling, it depends on the class and how much information the educator needs. 

Using traditional testing methods designing and collecting diagnostic data was a difficult task, however, by implementing online testing platform technology, such as TAO, educators can design, implement, and analyze diagnostic and other assessment formats quickly and efficiently. In doing so, educators can deliver targeted lessons, enhance student engagement, and, ultimately, increase student growth and achievement.