Fri, Apr 16, 2027Spring (Semester 2) · Week 13Day 45 of 6180-min blockCalendar fit

Claim graph submit

Essential question: What makes an environmental claim finished and trustworthy enough to submit, and not just done?Enduring understanding: A claim is only as strong as it is traceable: every data point needs a source, and the claim can never say more than the graph actually shows, or the whole argument collapses under one question.

Safety gate · before any work

  • Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
  • Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.

Do now

Finalize and submit your environmental claim graph with supporting CER analysis.

DueTonight, 11:29 PM
Hand in
Finalized claim graph package: labeled data table, graph with titled scaled axes, CER paragraph, data-source citations, and outlier notes.
Where
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.

You get two school days for every day you were absent, so this deadline moves with you.

Where you are · this course
Data tables, graphical claims, variables, outliers, correlation vs causation. Claim graph submit ▸ Day 3
Day 45 of 61 this semester16 left before WebXam
🧬 Where you are · PLTW
Biomedical InnovationProblem 4: Investigating Environmental Health"Activity 4.1.3 Testing the Waters", "Project 4.1.4 Dose Response"
Matched to your live myPLTW course (verified June 2026).
Today's driving question

You are about to submit your claim graph. Does every number trace back to a source, and does your written claim stay inside what the graph can actually prove?

Today you'll be able to

Finalize and submit your environmental claim graph with supporting CER analysis.

You've got it when
  • Your submission pairs an accurate graph with a valid CER.
  • The claim graph is cited and submitted.
Due today · Lab report RequiredFinalized claim graph package: labeled , graph with titled scaled axes, CER paragraph, data-source citations, and outlier notes.
Do-Now · start these with your notes closed
  1. Why does a claim that goes beyond what the graph shows count as unsupported, even if it feels true?
  2. What is the very last step that actually makes your submission count in this class?
Do this · step by step
numbered so we can always find our place
  1. 1Combine your , graph, and CER paragraph.
  2. 2Verify axis labels, units, and outlier notes are correct.
  3. 3Add citations for the data source.
  4. 4Check that the claim is fully supported by the graph.
  5. 5Submit the claim graph and confirm it in your tracker.
Interrupted or lost? Picking back up? Check whether your table, graph, and CER are combined into one piece (step 1). If yes, verify labels and citations (steps 2 to 3). The final move is always: submit and confirm in your tracker (step 5).
Optional project open: Microbiology & the Working Lab - solo or group, about 3 to 4 hours total. Due by Fri, May 28, 2027. Great WebXam prep.
The story

What did this day actually feel like?

Claim graph submit

Graph and paragraph.

Turned in: lab report → Lab Reports folder

Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.

The comic

The same day, drawn.

Drawing, panel 59: Claim graph submit.

Graph and paragraph.

Panel 59Claim graph submit · 2027-04-16
Read week 12, 4 panels

Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.

🛠 Get unstuck · pick your level

Run the lab
Combine table, graph, and CER; verify axis labels, units, and outlier notes; add source citations; confirm the claim stays inside what the graph shows; then submit and confirm in your tracker.
Absent? Async catch-up
Absent? Focus on the one thing that fails submissions most: add a source citation to every data point and check that your claim does not overreach. Then submit and confirm the tracker entry, because unconfirmed means uncounted.

Lab day: Tier 1 is the whole class at the bench. No extension today.

🔑 Today's words · 5

graphtrendoutliererrorcorrelation
+1 more in the word bank

Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.

Today's study notebook
Heavy-metal and environmental exposure: how toxins reach the body and how we measure and reduce risk.
Open the notebook
Watch first: today's 1-minute intro
Audio overviewVideo overviewMind mapStudy guideFlashcardsQuizData table
Where this fits
Tested on (Ohio WebXam)
Biotechnology for Health and Disease · 072125 (likely, pending confirmation)
PLTW lesson
BI · Problem 4: Investigating Environmental Health
WebXam domain
Microbiology Testing and Technology
Evidence to produce
Lab report
Do the work · 80-minute blockfirst 5 min = hook

💡 Big idea: A submission counts only when every point is traceable and the claim stays inside the graph, so that a stranger can verify your argument and the tracker confirmation makes it officially exist.

  1. 0-5 minWarm-up: what is the one thing still wrong or missing in your graph?
  2. 5-20 minCombine , graph, and CER into one document
  3. 20-40 minVerify axis labels, units, and outlier notes; add data-source citations
  4. 40-55 minConfirm the claim is fully supported by graph values
  5. 55-68 minFinal partner check: can they identify the claim and its evidence?
  6. 68-80 minSubmit claim graph and confirm in tracker
Mr. Mendoza's 5-minute intro
  • Today we close out the graphing unit with a polished, submission-ready package.
  • We're combining the , the graph, and the CER paragraph into one complete artifact.
  • Every number needs a citation. Every axis needs a label. Every claim needs the graph to back it.
  • When you submit today, Problem 4 graphing is done.
Know by the end
  • Every data point in a submission needs a traceable source citation.
  • The claim and the graph must align: a claim that goes beyond the data is unsupported.
  • Tracker confirmation is the last step that makes the submission count.
Open this PLTW section today

Data tables, graphical claims, variables, outliers, correlation vs causation. · Claim graph submit

Day 3 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.

Do this: Open Problem 4 in your myPLTW course shell and confirm Problem 4 graphing activities are complete, then finalize and submit your environmental claim graph.

Complete

Submit your finalized claim graph to the Problem 4 portfolio.

How far to get

Graphing should be fully wrapped up today; no Problem 4 graphing items should remain open after this submission.

Upload as evidence

Screenshot of your LMS submission confirmation as final evidence.

The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.

Today's PLTW tracker · fill in and submit

Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.

Use the code Mr. Mendoza gave you, not your name. Saved on this device.

Data tables, graphical claims, variables, outliers, correlation vs causation.Day 3 of this projectSee the full week plan
Today's PLTW target

Data tables, graphical claims, variables, outliers, correlation vs causation. · Claim graph submit

Open Problem 4 in your myPLTW course shell and confirm Problem 4 graphing activities are complete, then finalize and submit your environmental claim graph.

Graphing should be fully wrapped up today; no Problem 4 graphing items should remain open after this submission.

This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.

1 · What you do today

🎯 Finalize and submit your environmental claim graph with supporting CER analysis.

  • Combine your , graph, and CER paragraph.
  • Verify axis labels, units, and outlier notes are correct.
  • Add citations for the data source.
  • Check that the claim is fully supported by the graph.
  • Submit the claim graph and confirm it in your tracker.
2 · What you turn in

Lab report: Finalized claim graph package: labeled , graph with titled scaled axes, CER paragraph, data-source citations, and outlier notes.

Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.

3 · Who's doing what (team)
TaskWho
Combine your , graph, and CER paragraph._______
Verify axis labels, units, and outlier notes are correct._______
Add citations for the data source._______
Check that the claim is fully supported by the graph._______
Submit the claim graph and confirm it in your tracker._______

Working solo? Put your own name in "Who" for every row.

4 · Words I can use correctly
5 · I'm successful today when I can…
  • Your submission pairs an accurate graph with a valid CER.
  • The claim graph is cited and submitted.
6 · Reflection & next steps
Where are you today?0/7 checked
Pick your period and code first.
Your 4 steps today
  1. 1
    Do this
    Finalize and submit your environmental claim graph with supporting CER analysis.
  2. 2
  3. 3
    Submit this
    Lab report: Finalized claim graph package: labeled data table, graph with titled scaled axes, CER paragraph, data-source citations, and outlier notes.
  4. 4
    Submit it here
    1. 1Open the drop folder.
    2. 2Sign in with your district Microsoft account, not a personal one.
    3. 3Upload the file, named Lastname_Firstname__Assignment Title.
    4. 4Your own upload panel says Uploaded with a green check: that is your receipt.
    Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Biotechnology for Health (Biomedical Innovations) › Data tables, graphical claims, variables, outliers, correlation vs causation. › Lab report
    Open the drop folder
Were you absent? Jump to the make-up plan
Learn it · deck, reading, and vocabulary
Socratic teaching slide deck

The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.

Generated from this lesson's canonical data with a red-team citation check.

Carry forward

A CER paragraph converts a graph into an argument because it forces you to name the exact number and the exact reasoning, so a reader can check your logic instead of trusting your impression.

Daily take-home

A submission counts only when every point is traceable and the claim stays inside the graph, so that a stranger can verify your argument and the tracker confirmation makes it officially exist.

Inspect the analogy

A detective board holds observations, possible explanations, and one next question.

  1. Which notes are direct observations?
  2. Which notes are explanations?
  3. What new evidence would separate the explanations?
Rule

Keep observations separate from explanations, then collect the evidence that can distinguish the options.

Where it breaks

Biomedical investigations use controlled procedures and validated measurements, not intuition alone.

Map the analogy to biology
  • Board notes map to E1-E3.
  • Possible explanations map to the decision options.
  • The next question maps to the evidence-based action.
Read this first

Driving question: You are about to submit your claim graph. Does every number trace back to a source, and does your written claim stay inside what the graph can actually prove?

What you already know: A CER paragraph converts a graph into an argument because it forces you to name the exact number and the exact reasoning, so a reader can check your logic instead of trusting your impression.

New idea: A submission counts only when every point is traceable and the claim stays inside the graph, so that a stranger can verify your argument and the tracker confirmation makes it officially exist.

Visual or model: F1. F1. A lesson illustration or teaching diagram for Claim graph submit. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled system, test, or design relationship and identify which evidence should trigger revision.

  1. Observe or measure the relevant feature in Claim graph submit.
  2. Organize the observation with a stable evidence ID.
  3. Apply this rule: Keep observations separate from explanations, then collect the evidence that can distinguish the options.
  4. Choose the option the evidence supports and state the limit of the conclusion.

Real biomedical example: You are about to submit your claim graph. Does every number trace back to a source, and does your written claim stay inside what the graph can actually prove?

What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.

What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.

Vocabulary:
  • graph: A visual display of data, such as a bar, line, or scatter plot, that makes patterns and relationships easier to see than a table of numbers.
  • trend: The general direction that data moves over time, such as rising, falling, or staying steady, seen across many points rather than a single value.
  • outlier: A data point that lies far away from the rest of the values in a set, which may signal an error or a genuinely unusual result.
  • error: The difference between a measured value and the true value, caused by limits of instruments, method, or the person measuring.
  • correlation: Two things tending to occur together, which does not by itself prove that one causes the other.
  • causation: When one factor actually brings about another, shown by controlled evidence rather than by the two simply appearing together.

Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.

Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.

Evidence set and decision
E1 · Observation

Every data point in a submission needs a traceable source citation.

Limit: E1 supplies context or an observation; it does not by itself establish the explanation.

E2 · Mechanism

A submission counts only when every point is traceable and the claim stays inside the graph, so that a stranger can verify your argument and the tracker confirmation makes it officially exist.

Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.

E3 · Result

Your submission pairs an accurate graph with a valid CER.

Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.

PLTW-BFH-2027-04-16 · Simulated classroom evidence scenario

Your role: biomedical design team member

Decision: Your team must decide what the evidence from Claim graph submit supports before submitting the lab report named on the lesson page.

  • Select the option best supported by E1-E3.
  • Select a reasonable alternative and name the evidence it would require.
  • Delay the claim because the evidence does not distinguish the options.

Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the lab report.

Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Claim graph submit. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.

Composite case file · PLTW-BFH-2027-04-16

Reason for review: Your team must decide what the evidence from Claim graph submit supports before submitting the lab report named on the lesson page.

Context: A claim is only as strong as it is traceable: every data point needs a source, and the claim can never say more than the graph actually shows, or the whole argument collapses under one question.

Timeline:
  • T1: Combine your , graph, and CER paragraph.
  • T2: Verify axis labels, units, and outlier notes are correct.
  • T3: Add citations for the data source.
  • T4: Check that the claim is fully supported by the graph.
  • T5: Submit the claim graph and confirm it in your tracker.
Evidence records:
  • E1: Every data point in a submission needs a traceable source citation.
  • E2: A submission counts only when every point is traceable and the claim stays inside the graph, so that a stranger can verify your argument and the tracker confirmation makes it officially exist.
  • E3: Your submission pairs an accurate graph with a valid CER.

Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.

Figure finding: Teaching diagram for Claim graph submit. Trace the labeled system, test, or design relationship and identify which evidence should trigger revision. This is a teaching model, not patient or experimental data.

Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.

Math moment
Formula or setup

Mean = sum of values / number of values. Median = middle ordered value. Range = maximum - minimum.

Worked parallel example

For 2, 4, 4, and 10: mean = 20 / 4 = 5, median = 4, and range = 10 - 2 = 8.

Units and reasonableness

Mean, median, and range keep the measurement unit. Order the values before finding the median.

Try it with today's data

Calculate the requested summary for today's supplied values, then write what it reveals and what it hides.

Watch the trap

Students often think Once the graph looks polished and the CER is written, the work is done and I can submit; citations and the tracker are just extra paperwork.. The trap: Polish is not proof. An uncited data point is unverifiable, so a reader cannot trust it, and an unconfirmed tracker entry means the submission does not exist in the system. Both are load-bearing, not paperwork.

Worked example · a parallel case (guides, does not reveal)
Finalized claim graph package with CER and citations
Completes: Completes the Problem 4 claim-graph deliverable: a labeled data table, a graph with titled scaled axes, a CER paragraph, data-source citations, and outlier notes.

Final package contents:

1. Data table: monthly PM2.5 with units (micrograms/m3), June flagged as an outlier.

2. Graph: line graph titled 'Monthly Roadway PM2.5', y-axis scaled 0 to 40 with units, x-axis months.

3. CER paragraph: claims summer PM2.5 is highest, cites the 35 vs 9 to 14 values, classifies the link as correlation, and names the wildfire alternative explanation.

4. Citation: city air-quality monitoring data (agency report), accessed this term.

Alignment check: My claim says 'highest in summer in this dataset,' which the graph fully supports. I did not claim summer causes the spike, because the data only shows correlation, so the claim stays within the evidence.

Tracker: marked the claim graph as submitted.

Line graph of monthly PM2.5 declining from January then spiking to 35 in June.
Why this matters

This model shows the level of evidence and organization needed to complete: Completes the Problem 4 claim-graph deliverable: a labeled data table, a graph with titled scaled axes, a CER paragraph, data-source citations, and outlier notes.

Build yours step by step
  1. State the question and method.
  2. Present the observations and data with units.
  3. Explain the result, limitations, and next investigation.
Change it for a new task

Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.

Also due today: Submit the finalized claim graph on the class site and confirm in your tracker.

See the full worked example
Portal terms
CER:
Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
SOP:
Standard Operating Procedure, the exact steps to follow (especially in a lab).
Tracker:
Your PLTW progress log where you record completed evidence.
myPLTW:
The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
This unit's vocabulary

Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.

Build your vocabulary · optional, for extra credit

Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Claim graph submit. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.

graph
trend
outlier
error
correlation
causation

Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.

Teacher-posted resources

Classroom documents for this lesson are posted in Schoology. Open Clever, then Schoology, and find each one by the name shown on its card.

Use during lessonFor: Everyone
BI Activity 4.1.1 Environmental Exposures
worksheet/handoutPosted in Schoology
Open in Schoology

Open this when the class reaches this activity and use it to complete the required lesson artifact.

Placement rationale

Matched Environmental data graphing and analysis by path:Biomedical-Innovations/Problem-4_Environmental-Health/4.1_Environmental-Health; keywords:environmental. Score 134. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).

Catch-up / reteachFor: Need extra support
BI 4.1.1 Tox Town Concept Map (Williams Family)
worksheet/handoutPosted in Schoology
Open in Schoology

Use this if you were absent, got stuck, or need another pass before you submit the lesson artifact.

Placement rationale

Matched Environmental data graphing and analysis by path:Biomedical-Innovations/Problem-4_Environmental-Health/4.1_Environmental-Health; keywords:environmental. Score 130. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).

Catch-up / reteachFor: Need extra support
BI 4.1.2 Water Contamination Activity Overview
worksheet/handoutPosted in Schoology
Open in Schoology

Use this if you were absent, got stuck, or need another pass before you submit the lesson artifact.

Placement rationale

Matched Environmental data graphing and analysis by path:Biomedical-Innovations/Problem-4_Environmental-Health/4.1_Environmental-Health; keywords:environmental. Score 130. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).

How to get there: open Clever and sign in with your Microsoft (district) account. Both myPLTW and Schoology are in Clever. Do the activity in myPLTW. Turn the work in on this site or hand it to Mr. Mendoza, because that is the step that counts as submitted. Schoology only shows your report-card grade later.

Check yourself · commit, then reveal

Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Claim graph submit. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.

Quick self-check · commit, then reveal

Your graph shows nitrate levels at 3 sample sites. Your claim reads: 'Nitrate pollution is rising across all of Cleveland's water.' Is this ready to submit? Fix it.

How sure are you?

Write an answer and pick a confidence to unlock the key.

Cumulative WebXam review · flash practice

Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.

Tap an answer to check it · nothing is recorded or graded
[Review: Making the call: bias, error, graph choice, and a CER conclusion] An SDS lists a corrosive pictogram and the statement “causes severe skin burns,” but the PPE section says no gloves are required. Why is this incorrect?
[Review: Validating Your Prototype: literature review, decision matrices, and metrics] A team uses a decision matrix to choose among prototype designs. What is the main purpose of this tool?
[Review: Environmental Exposure: pathways, dose, and public-health risk] When assessing the risk of a pollutant to a community, which two factors must be considered together?
A researcher wants to show how an air pollutant's concentration changed over a 30-day period. Which graph type is most appropriate?
Go further and get help
Lab · prepare, conduct, complete
1Prepare
Pre-lab pass · clear all six to go to the bench
0/6

I can name the procedure's purpose and the evidence I will record. I can identify each named hazard and the control that reduces it: Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start. My data table is ready before materials are handled.

Finish the checklist before you handle any material.

Safety · specific to today's hazards
  • Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
  • Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.
Review Lab Safety (rules, PPE, SDS, emergencies) and check your contract + test
2Conduct (Argument-Driven Inquiry)
  1. 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
  2. 2Combine your data table, graph, and CER paragraph.
  3. 3Verify axis labels, units, and outlier notes are correct.
  4. 4Add citations for the data source.
  5. 5Check that the claim is fully supported by the graph.
  6. 6Submit the claim graph and confirm it in your tracker.
  7. 7Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
  8. 8Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
Prepare this data table before materials are handled
Trial or sample IDIndependent conditionMeasured result with unitsObservation before interpretationQuality-control note
     
     
     
3Complete
Argue from your evidence, then compare what you predicted to what happened. Error analysis names a specific method limit, never "human error".
You predicted

Before the procedure, predict the result and cite the rule behind the prediction.

What actually happened

After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.

Your lab report is graded on the rubric below, with extra weight on error analysis and method.
Where this leads: careers
What to do if you were absent
If YOU are absent

Today is individual work you can do from home: complete the same target above, then submit your Lab report.

Open the drop folder

Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.

If MR. MENDOZA is absent

Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:

Khan Academy Statistics
Optional extra credit (async)

You've passed Unit 2, so the optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.

Open the extra-credit track
How this is graded
For: Lab report: Finalized claim graph package: labeled data table, graph with titled scaled axes, CER paragraph, data-source citations, and outlier notes.
  • Complete
    Every required part of the artifact is present, nothing left blank.
  • Accurate
    The science and the data are correct and match the evidence.
  • Scientific reasoning
    You explain your claim with evidence and reasoning (CER), not just an answer.
  • Professional communication
    Clear, organized, labeled, and written the way a clinician or scientist would.
  • Submitted
    Turned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.
  • Error analysis and method · counts double
    Name a specific limit of the method and how it moved your result, and compare what you predicted to what happened. "Human error" does not count; say what about the procedure or instrument caused it.