A slide is one claim with the evidence that supports it. Nothing else belongs in the definition, and almost every bad slide violates it in the same way, by holding what the author knows about a topic without arguing anything about it.
How do you test whether a slide makes a claim?
The test takes four seconds, so try it on the next deck you open. Read the title. If the title is a noun phrase, the slide is a container. If the title is a sentence with a verb that could be contradicted, the slide is an argument, and the body's only job is to make the title believable.
| Container title | Argument title |
|---|---|
| Revenue by state | Three states now carry 71% of revenue, up 13.1 points in two years |
| Q2 performance | Gross margin is up 4.5 points, which is why gross profit grew 53.7% on 42.6% revenue growth |
| Pricing analysis | Volume can fall 18.6% before a ₹399 price beats ₹349, and history says it falls about 8% |
| Marketing update | Acquisition cost rose 16.6% in one quarter, concentrated in prospecting |
The right column takes longer to write, and that's the cost being paid deliberately. Writing "Revenue by state" requires knowing what data is on the slide. Writing "Three states now carry 71% of revenue, up 13.1 points in two years" requires knowing what the data means, having computed the 71.0% and the 13.1 points, and being willing to be wrong about both. The thinking happens in the title, so the title-is-the-message rule is one of the seven the machine checks.
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What follows from one claim per slide?
Two consequences follow, and both are unpopular.
The first is that a slide with two claims is two slides. When a title needs an "and" joining unrelated assertions, split it. The exception is a true compound claim where the second half is the consequence of the first, as in the gross-margin example above, where the 53.7% follows from the 4.5 points.
The second is that a slide with no claim isn't a slide. Agenda pages, section dividers and the "any questions" closer are navigation furniture, and they're fine as furniture. What isn't fine is the slide that presents four charts under the title "Market overview" because the author gathered four charts. If none of them makes a claim, none of them belongs, and that slide should have been a sentence in an email.
Which chart form fits which message?
The compact chart grammar below exists so the worked examples can name a form correctly. The chart-craft branch owns the full treatment, including the cases where these rules bend.
| Message type | Form | Ruled out |
|---|---|---|
| Comparison across categories | bar, sorted by value | pie above three parts |
| Change over ordered time | line | bar, when the periods are many |
| Change between exactly two periods | slope chart | two side-by-side pies |
| Part to whole, few categories | stacked bar | pie above three parts |
| Relationship between two variables | scatter | anything with a time axis |
| Two series on different units | small multiples, or index both to 100 | dual axes, always |
Four rules apply on top of the table and hold everywhere. One message per chart. The title states the message. Colour carries meaning or is neutral. Declutter before decorating. And a fifth that decides more charts than the rest combined: sort by value unless the order is intrinsic, because a category order is a claim about what matters, and alphabetical is a claim that nothing does.
Three forms are simply out. Dual axes, because the reader can't tell which axis a line belongs to and the author chose the scaling that makes the story look how they wanted. Three-dimensional effects, because they add ink that encodes nothing and distort the very comparison the chart exists to make. And the pie chart above three slices, because human eyes compare angles badly. In the Chandra Naturals state mix, the two smallest FY26 slices differ by 5.82 degrees out of 360, a difference no reader will see and every bar chart makes obvious.