Science Task Screener
Task Title: Mystery in the Lab: Forensic Chromatography & Poison Analysis
Grade: High School
Date: April 19, 2026
Instructions
- Before you begin: Complete the task as a student would. Then, consider any support materials provided to teachers or students, such as contextual information about the task and answer keys/scoring guidance.
- Using the Task Screener: Use this tool to evaluate tasks designed for three-dimensional standards. For each criterion, record your evidence for the presence or absence of the associated indicators. After you have decided to what degree the indicators are present within the task, revisit the purpose of your task and decide whether the evidence supports using it.
Criterion A. Tasks are driven by high-quality scenarios that are grounded in phenomena or problems.
i. Making sense of a phenomenon or addressing a problem is necessary to accomplish the task.
- Is a phenomenon and/or problem present?
Yes, the problem of identifying potentially toxic synthetic dyes in food through forensic chemistry.
- Is information from the scenario necessary to respond successfully to the task?
Yes, students must use the calculated Rf values and the provided FDA reference data to reach a conclusion about Candy B.
ii. The task scenario is engaging, relevant, and accessible to a wide range of students.
| Features of scenarios | Yes | Somewhat | No | Rationale |
|---|---|---|---|---|
| Scenario presents real-world observations | [X] | [ ] | [ ] | Uses real food dyes (Red 40, Yellow 5) and toxins (Rhodamine B). |
| Scenarios are based around at least one specific instance, not a topic or generally observed occurrence | [X] | [ ] | [ ] | Focuses on a specific shipment of “Candy B.” |
| Scenarios are presented as puzzling/intriguing | [X] | [ ] | [ ] | The mystery of “what dyes are hiding inside?” |
| Scenarios create a “need to know” | [X] | [ ] | [ ] | Students need to verify if the food is toxic. |
| Scenarios are explainable using grade-appropriate SEPs, CCCs, DCIs | [X] | [ ] | [ ] | Bulk properties and electrical forces. |
| Scenarios effectively use at least 2 modalities | [X] | [ ] | [ ] | Micro/Macro views and a data table. |
| If data are used, scenarios present real/well-crafted data | [X] | [ ] | [ ] | Polarity values and Rf results are chemically accurate. |
| The local, global, or universal relevance of the scenario is made clear to students | [X] | [ ] | [ ] | Food safety is a universal concern. |
| Scenarios are comprehensible to a wide range of students at grade-level | [X] | [ ] | [ ] | Clear instructions. |
| Scenarios use as many words as needed, no more | [X] | [ ] | [ ] | Clean laboratory-style interface. |
| Scenarios are sufficiently rich to drive the task | [X] | [ ] | [ ] | Requires testing multiple solvents to find the best separation. |
| Evidence of quality for Criterion A: [ ] No | [ ] Inadequate | [ ] Adequate | [X] Extensive |
Criterion B. Tasks require sense-making using the three dimensions.
i. Completing the task requires students to use reasoning to sense-make about phenomena or problems.
Students must reason that if a dye moves toward a polar solvent and sticks to the polar paper in non-polar solvents, it must have strong electrical forces of attraction to polar molecules, implying high polarity.
ii. The task requires students to demonstrate grade-appropriate dimensions:
Evidence of SEPs: Planning and Carrying Out Investigations: Choosing the correct solvent to maximize separation is a fundamental part of the experimental design.
Evidence of CCCs: Patterns: Recognizing that specific chemical structures yield consistent Rf patterns across different trials.
Evidence of DCIs: PS1.A: Inferring the strength of electrical forces (IMF) based on bulk-scale observations (chromatography bands).
iii. The task requires students to integrate multiple dimensions in service of sense-making and/or problem-solving.
The final “Verdict” requires using the experimental method (SEP) to prove a property of matter (DCI).
iv. The task requires students to make their thinking visible.
The formal report in Part 4 requires students to explain the “why” behind the separation using electrical forces.
| Evidence of quality for Criterion B: [ ] No | [ ] Inadequate | [X] Adequate | [ ] Extensive |
Criterion C. Tasks are fair and equitable.
i. The task provides ways for students to make connections of local, global, or universal relevance.
Forensic science is a popular and engaging entryway for many students.
ii. The task includes multiple modes for students to respond to the task.
Calculations, table entries, and narrative reports.
iii. The task is accessible, appropriate, and cognitively demanding for all learners.
Supports inquiry by allowing students to “fail” with the wrong solvent before identifying the correct one.
| Evidence of quality for Criterion C: [ ] No | [ ] Inadequate | [X] Adequate | [ ] Extensive |
Criterion D. Tasks support their intended targets and purpose.
Before you begin:
-
Describe what is being assessed. HS-PS1-3: Using bulk properties to infer molecular-level forces.
-
What is the purpose of the assessment?
- Formative
- Summative (Chemistry unit assessment)
| Evidence of quality for Criterion D: [ ] No | [ ] Inadequate | [X] Adequate | [ ] Extensive |
Overall Summary
An excellent chemistry task that uses a standard lab technique (chromatography) as a vehicle for understanding abstract concepts like Intermolecular Forces and Polarity.
Final recommendation (choose one):
- Use this task (all criteria had at least an “adequate” rating)