Safety and evidence boundary
Use only teacher- or parent-approved low-risk investigations, supplied datasets, paper models, or simulations. No human-subject experimentation, personal health data, biological culturing, unknown environmental samples, hazardous chemicals, animal manipulation, ingestion studies, or medical claims are permitted. If a proposed investigation cannot meet these limits, convert it to a data-analysis or model-based study.
Explicit science instruction
Data displays should match the question and the structure of the data. A bar chart can compare category summaries; a scatterplot can show relationships between paired quantitative variables; a line graph can show ordered or time-series change when connecting observations is meaningful. Tables remain important because graphs often hide exact values.
Useful summaries include counts, proportions, mean, median, range, percent change, rates, and measures of spread. The appropriate choice depends on distribution, sample size, outliers, and the question. Uncertainty should be reported rather than hidden.
Vocabulary: categorical data; quantitative data; mean; median; range; rate; percent change; scatterplot; time series; uncertainty; outlier.
Worked example with reasoning
Dataset A compares mean enzyme rate at four temperatures: a point or bar display with uncertainty may fit. Dataset B contains individual body-size and metabolic-rate pairs: a scatterplot is more informative because both variables are quantitative. Using four bars for Dataset B would discard the paired relationship.
Guided question
Why is choosing the graph after deciding what story you want to tell a threat to honest analysis?
Independent work
- Identify the data type in your investigation.
- Select a graph and justify the choice.
- Calculate at least one appropriate summary statistic.
- Mark missing data or uncertainty honestly.
- Write one pattern statement and one statement the graph cannot establish.
Misconception check
A mean is not automatically the “best” summary. Strongly skewed data or extreme outliers may make the median or a full distribution more informative.
Formative understanding check
When is a scatterplot preferable to a line graph?
Show the worked response
When the goal is to examine the relationship between paired quantitative variables without implying that observations form a continuous sequence in time or another ordered dimension.
Open-book formative practice only; not an official mastery attempt or grade.
Mentor evidence conference
Ask Archaemenes to challenge the alignment among your question, method, data, graph, claim, and limitations. The mentor may critique reasoning but does not approve unsafe procedures or provide protected assessment answers.
Open Archaemenes for this lessonTeacher guidance
Foundation: use a graph-choice decision guide and calculate one supplied statistic. Core: choose and defend the graph and summary from the actual dataset. Extended: compare alternate displays and explain how each can reveal or conceal different patterns.
Preserve learning evidence
Keep the research question, model, method, data display, CER, correction record, and limitations in the matching Week 17 evidence field and semester portfolio.
Return to wednesday Evidence Workspace