Error Bar Type Enforcement

Why Licklider requires error bar type to be declared, what the three options mean, and how this affects claim-bearing export.

Error bars on group comparison figures can represent three different things: the spread of values in the data, the precision of the mean estimate, or a range within which the true mean is likely to fall. These three interpretations lead to very different readings of the same figure, and they are frequently confused in published research.

Licklider requires that the error bar type is declared before a figure can be used in a claim-bearing context.

The three error bar types

Standard deviation (SD)

Shows the spread of individual values around the group mean. A wider SD bar means the data is more variable. SD does not depend on sample size — adding more observations does not shrink an SD bar if the underlying variability stays the same.

Use SD when the figure is showing the distribution of values in the sample — for example, when communicating biological variability.

Standard error of the mean (SEM)

Shows the precision of the estimated group mean. SEM is calculated as SD divided by the square root of n, so it shrinks as sample size increases. A figure with SEM bars can look more precise than one with SD bars even when the underlying data is identical.

Use SEM when the figure is making a statement about the estimated mean — but be aware that SEM bars are often misread as describing the spread of the data.

95% confidence interval

Shows a range within which the true group mean is estimated to fall with 95% confidence. Like SEM, CI shrinks with sample size. Unlike SEM, CI is directly interpretable as a statement of uncertainty about the mean.

Use 95% CI when the figure is intended to communicate uncertainty about the mean in a way that readers can directly interpret.

What Licklider asks you to confirm

When a figure contains error bars, Licklider confirms which type was used before the figure can be exported in a claim-bearing context. The confirmation presents the three options above and asks you to select the one that matches your analysis.

The selection is recorded in the figure's disclosure and appears in the exported output.

Effect on export

If the error bar type has not been declared, claim-bearing export is blocked. The Inspector will indicate that the error bar type is unresolved.

For exploratory analyses, the figure can be viewed and shared without declaring the error bar type, but the declaration is required before the result can be used as a formal claim.

Which figures are affected

The error bar type check applies to figures that display error bars, including:

  • Group comparison mean figures
  • Bar charts with error bars
  • Line charts with error bars
  • Dot plots

Strip plots, violin plots, and box plots show the underlying data or distribution directly and are not subject to this check.

What this page does not cover

  • How error bar type is set when requesting a figure → specify in the Chat when requesting the analysis
  • Effect size reporting alongside error bars → see Effect Size, CI, and N Reporting