A 50-minute lesson focusing on the CERNU conclusion framework (Claim, Evidence, Reasoning, Next steps, Unanswered questions). Students learn to analyze experimental data, connect claims to evidence, and formulate professional scientific conclusions using a detective-themed investigation approach.
Students simply repeat measurements instead of explaining the science. Remedy: Direct them to reference microscopic snagging and the conversion of energy.
All CERNU elements are flawless. Reasoning covers molecular friction, notes experimental variables/improvements (Next Steps), and asks a testable research question (Unanswered).
Advanced
Score 3.0
Claim is correct (no personal pronouns) with quantitative Evidence (cm units). Reasoning covers basics of surface friction. Generic next steps.
Proficient
Score 2.0
Drafts a basic conclusion but contains minor errors: missing metric units on some numbers, claim contains "I think...", or reasoning restates data without science.
Approaching
Score 1.0
Needs helper prompts. Missing multiple components of the CERNU model. Data points are inaccurate, and claims/reasoning do not link logically to the block experiment.
Emerging
Quick Reference Answer Key (Detailed Replicas Follow on Pages 3-6)
Curiosity Case File (Page 3)
• Claim: B (Dad ate the missing cookies).
• Evidence: Dusting of flour, size-11 prints, milk quote.
• Reasoning: Flour links Dad's apron to counter prep, boot prints match crumb footprint trails, while Quote establishes perfect motive.
CERNU Lineup Sorting (Page 6)
• C Claim: Card A (temperatures rise, rates rise)
• E Evidence: Card B (At 35°C lost 14.5 mL vs 2.1 mL)
• R Reasoning: Card C (kinetic energy water bonds)
• N Next Steps: Card E (additional trials, sensors)
Investigator Training Briefing: Tomorrow, we will begin formal science experiments using data. Today, we are training your detective instincts. Below is an everyday household mystery. Use your logical reasoning to solve it!
INCIDENT BRIEFING
THE CASE OF THE MIDNIGHT BAKER
Mrs. Pav placed a dozen freshly baked chocolate cookies on the kitchen counter at 9:00 PM. By 6:00 AM, three cookies were completely missing, and a trail of crumbs led toward the hallway.
The Investigation Unit gathered the following physical clues at the scene:
Clue A: A light dusting of white flour on Dad's favorite blue apron hanging near the pantry.
Clue B: Large size-11 boot prints stamped in cookie crumbs leading away from the counter.
Clue C: Dad was overheard saying, "Nothing beats hot cookies with milk!" at 11:30 PM last night.
1 Part I: Identify the Claim (The Accusation)
Based on the briefing clues above, which statement acts as the single best direct answer to our mystery?
A
The family dog jumped onto the high counter and ate the cookies.
B
Dad baked or ate the missing chocolate cookies at some point during the night. [ CORRECT CLAIM ]
C
Mrs. Pav miscounted and only baked nine cookies in the first place.
2 Part II: Connect Evidence to Reasoning
List the three primary pieces of physical evidence that back up your choice:
Evidence #1: A light dusting of white flour found on Dad's blue apron (Clue A).
Evidence #2: Size-11 boot prints stamped in the crumb trails near counter (Clue B).
Reasoning: Write 2 sentences explaining WHY the apron, footprints, and Dad's quote logically prove your accusation.
"The white flour connects Dad's blue apron directly to counter kitchen preparation work, matching the crumb trail footprints left at the scene that matched his size-11 boot prints."
"Furthermore, his overheard midnight comment establishes perfect motive, intent, and places him inside the kitchen during the exact timeline the cookies went missing."
Curiosity Case File Answer Key — SIB Master Key Dossier Replica Reference — Page 3 of 6
ANSWER KEY MASTER
Evidence Notebook
REPLICA MASTER
AGENT: S.I.B. RECRUIT KEY
DATE: 08 / 19 / 2026
SQUAD: TEACHER
Mission Parameter: Analyze data tables and draft high-quality scientific conclusions using the five pillars of the CERNU framework.
Investigation Blueprint: Guided Notes
C
CLAIM One sentence statement
A clear, direct answer to the original scientific question. It does NOT include statistical evidence/data or the word "because".
E
EVIDENCE The Raw Proof
Specific qualitative and quantitative data/observations collected during the test. Every piece of quantitative evidence MUST include exact numbers and scientific metric units (e.g., °C, mL, cm).
R
REASONING The Science Bridge
An explanation of how/why your evidence supports your claim. This is where you explain the background scientific concepts (such as friction, cellular respiration, or phase changes).
N
NEXT STEPS Experimental Upgrades
A plan to address experimental errors/mistakes or raise testing trials, or a proposal of new variables to investigate in future iterations.
U
UNANSWERED QUESTIONS The Curiosity Loop
A new, testable, open-ended scientific/research question that was sparked by this experiment's results.
Co-Investigation Case File: The Soggy Plant
Based on the data table shown on Slide 11, record the key takeaways constructed as a class:
Class Claim Draft:
"Bean plants watered with 20 mL of water daily grow significantly taller over two weeks than those watered with 0 mL or 100 mL."
Answer the question directly (no personal pronouns)
Class Evidence Bullet Points:
"Over 2 weeks, 20 mL water bean plants reached an average height of 14.2 cm, whereas 0 mL water plants grew 0.5 cm, and 100 mL plants grew 3.8 cm."
How does the surface material of a runway affect the sliding distance of a weighted wooden block?
An investigation team launched a weighted block across four different surfaces with identical starting force. The block's final sliding distance was recorded. All tests were conducted under controlled classroom temperature and with the same wooden block.
Runway Surface Material (Independent Variable)
Avg. Slide Distance (Dependent Variable)
Surface Profile Notes
Polished Ice Runway
45.2 cm
Minimal texture, extremely smooth
Laminated Desktop
22.4 cm
Standard flat desktop workspace
Fine Sandpaper (Grit 220)
12.1 cm
Abrasive, rough gritty layer
High-Pile Felt Carpet
3.2 cm
Thick, dense wool fibers
C Claim (Write 2 direct sentences answering the inquiry question)
"As the roughness of the runway surface material increases, the average sliding distance of the wooden block decreases."
"Ice produced the absolute longest sliding distance, while high-pile felt carpet had the shortest sliding distance."
E Evidence (Incorporate metric numbers and units, contrast ice & felt runway points)
"The block slid furthest on polished ice at 45.2 cm. Under identical launch force, laminated desktop yielded 22.4 cm, rough sandpaper yielded 12.1 cm,"
"and high-pile felt carpet yielded the absolute shortest sliding distance at only 3.2 cm."
R Reasoning (Explain WHY: Use the science concept friction to bridge the gap)
"This occurs due to kinetic friction. Rougher surfaces have higher coefficients of friction due to microscopic ridges that snag and resist the block's movement."
"This mechanical friction converts kinetic energy directly into thermal energy, decelerating the block at a much faster rate on carpet compared to smooth polished ice."
N Next Steps (How could we reduce experimental errors or raise trial counts next time?)
"To reduce errors, we should perform five trials per surface to calculate average distances, and utilize an electronic release gate to stabilize force."
U Unanswered Question (Write a fresh, testable, relevant research question born from these findings)
"How would adding a liquid lubricant (such as standard cooking oil or water) to the desktop runway affect the overall sliding distance of the weighted wooden block?"
Proficiency: [ 4.0 MASTER KEY ] Case Status: [X] Solved
ANSWER KEY MASTER
FIELD EXERCISE — CO-OP LAB
CERNU Lineup Activity
REPLICA MASTER
Mission Parameters: Work with a partner. Cut out the 8 "Clue Cards" at the bottom of this page. Sort and place them into the correct Case Folder slots in the vault above. Be careful: 3 cards are Red Herrings (flawed logic/opinions) and must be discarded into the trash!
1. The Case Dossier Vault (MASTER SORTING PLACEMENT KEY)
[ C ] CLAIM SLOT
CORRECT PLACEMENT: CARD A
"As environmental temperature rises, water evaporation rates inside the closed chamber increase."
[ E ] EVIDENCE SLOT
CORRECT PLACEMENT: CARD B
"At 35°C, the water lost 14.5 mL over 2 hours, whereas at 15°C, the water lost only 2.1 mL."
[ R ] REASONING SLOT
CORRECT PLACEMENT: CARD C
"This occurs because higher temperatures transfer kinetic energy, water particles break bonds."
[ N ] NEXT STEPS SLOT
CORRECT PLACEMENT: CARD E
"To improve reliability, we should run five additional trials per temperature point to reduce error."
[ U ] UNANSWERED SLOT
CORRECT PLACEMENT: CARD F
"How does wind speed across the mouth of the chamber affect the overall rate of water evaporation?"
RED HERRING TRASH DISCARD
TRASH DISCARDS
Glue Cards D, G, H (flawed personal opinions, missing units, magic evaporation reasoning)
Lineup Cards Key Summary: Card A (Claim) | Card B (Evidence) | Card C (Reasoning) | Card D (Trash) | Card E (Next Steps) | Card F (Unanswered) | Card G (Trash) | Card H (Trash).
