Bias, error, graph choice
Thu, Mar 11, 2027 · Week 8 · Biotechnology for Health (Biomedical Innovations)
Today's goal: Identify sources of bias and error and choose the right graph for your physiology data.
What a finished product looks like
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Comparison: mean heart rate at rest vs after light activity.
Graph choice: a bar graph, because I am comparing the mean of two categories (rest, activity), not a trend over continuous time. Bars make the two means easy to compare side by side.
Axes: x-axis = Condition (Rest, After activity); y-axis = Mean heart rate (bpm), starting at 0 so the bars are not visually exaggerated. Title: 'Mean Heart Rate by Activity Condition'. I added error bars showing the standard deviation.
Bias-and-error note:
- Possible bias: I tested only one subject, so the result may not represent other people (selection bias).
- Possible measurement error: sensor placement could shift between trials, adding noise. I reduced this by keeping the sensor in the same spot.
- How it shows in the graph: the SD error bars make the measurement spread visible, so a reader can see the difference is larger than the within-group variation.
Also due today: Submit your graph draft with bias-and-error note to the Schoology assignment by end of period.
WebXam problem for today's skill
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.