Reporting Chemical Data: Statistics, Figures and Data Availability · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Report results others can build on

Science · Chemistry · ages 23-24
Name ______________________   Date ____________

  1. True or false: a figure that shows only the mean of each group can hide the fact that the measurements were widely scattered or overlapped a lot between groups.

    Circle one:   True   False

  2. A chemist weighs the same powder sample three times and gets 2.41 g, 2.45 g, and 2.43 g. What is the mean of the three measurements, in grams? Give your answer to two decimal places.

    Answer: ______________

  3. What should accompany every reported result?

    • The replicate count and a matching uncertainty
    • A larger font size
    • A shorter title

  4. Open sharing lets others check calculations, redraw figures, and repeat experiments.

    Circle one:   True   False

  5. Which raw files should you deposit for a stated result?

    • Only the polished summary table
    • The readings behind it, in usable form
    • An unrelated older dataset

  6. True or false: when two groups are compared, like fuel efficiency of manual and automatic cars, reporting only the two means without the group sizes or the spread is enough for a reader to judge the conclusion.

    Circle one:   True   False

  7. A student repeats a measurement 3 times and gets values that vary a little. Which report of the result is the most complete and honest?

    • The result is 2.43 g.
    • The result is about 2.4 g, more or less.
    • The result is 2.43 g, the mean of 3 measurements, with a standard deviation of 0.02 g.
    • The best measurement was 2.45 g, so that is the result.

  8. A results section gives single yields with no uncertainties. What do you ask for?

    • Fewer significant figures only
    • Bolder claims
    • Repeat counts with matching uncertainties

  9. Two labs clash over one mean each, both hiding points. What resolves it?

    • Averaging the two means
    • A louder argument
    • Full points with uncertainties and raw files from both

  10. Depositing only the polished table counts as sharing data others can build on.

    Circle one:   True   False

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Answer key

For grown-ups. Fold this page away before handing over the rest.

Report results others can build on W1-mt_P3RFmE6LzI-s1

  1. True · Means can look identical even when the underlying points are very different. Only a figure that shows the points themselves reveals the real spread.
  2. 2.43 · The mean is the sum of the measurements divided by how many there are. Reporting the mean together with the number of repeats is the first step toward an honest result.
  3. The replicate count and a matching uncertainty · Repeats and uncertainty say how firm the number is.
  4. True · Reachable raw files make checking possible at all.
  5. The readings behind it, in usable form · Retracing needs the readings, not the polish.
  6. False · Without knowing how many observations went into each group and how scattered they were, a reader cannot tell whether a difference between means is real or just luck.
  7. The result is 2.43 g, the mean of 3 measurements, with a standard deviation of 0.02 g. · A trustworthy report states how many times the measurement was repeated and how spread out the repeats were, not just one number.
  8. Repeat counts with matching uncertainties · Single numbers with no backing cannot be built on.
  9. Full points with uncertainties and raw files from both · Visible spreads plus files show whether the means even disagree.
  10. False · Strangers need the readings to retrace and extend the work.
Worksheet · LightMySky