Two workshop notices say “Saturday, 10 a.m.” That detail belongs in the overlap. Only one says registration is required, so registration belongs on that workshop's side. The price is absent from both notices. An omitted detail belongs under “Not established,” not automatically under “Both.”
Use the worked Venn diagram template to sort the details, check their source lines, and write a comparison that says only what the notices support.
Compare the same feature in both notices
The two notices are original fictional examples:
| Notice A | Notice B |
|---|---|
| Watercolor drop-in | Origami workshop |
| Saturday, 10 a.m. | Saturday, 10 a.m. |
| Library activity room | Library activity room |
| Supplies provided | Supplies provided |
| Drop in; no registration required | Registration required |
The overlap holds Saturday at 10 a.m., Library activity room and Supplies provided. Notice A's side holds watercolor and no registration required. Notice B's side holds origami and registration required.
Neither notice supplies a price. “Both are free” is therefore unestablished. “Supplies provided” answers who supplies materials; it does not answer whether attendance has a fee.
NCTE's Venn diagram guidance places shared characteristics in the overlap and object-specific features outside it. It also asks learners to explain their placements. This example adds an unknown category so a missing fact cannot silently become a shared one.
Place a card and explain your choice
Choose Saturday, 10 a.m., select Both, and press Check placement. The result points to the time line in each notice. Try putting Registration required in Both; the explanation shows Notice A's explicit no-registration wording and Notice B's requirement.
Next choose Free entry. Select Not established and check it. There is no price line to cite. Keeping that card outside the circles preserves the distinction between “different” and “unknown.”
The controls check these supplied feature cards against the two authored notices. They do not determine whether an arbitrary real-world claim is true. For another pair of texts, replace the cards and their evidence together.
On a narrow screen the three diagram regions stack into labeled areas: A only, Both and B only. The labels carry the comparison even when overlapping circles would leave too little room to read.
Turn the diagram into a sentence
A supported comparison is:
Both fictional workshops meet on Saturday at 10 a.m. in the library activity room and provide supplies. The watercolor session allows drop-ins without registration; the origami workshop requires registration. Neither notice states a price.
That last sentence keeps an unanswered practical question visible. Someone planning to attend should check the actual organizer's current information before deciding what to bring or pay.
For a class comparison, give learners a blank explanation area. Ask for one shared feature, one difference and the lines supporting each. A partner can check whether the same feature was compared on both sides before discussing sentence style.
Copy this prompt for another comparison
Make a self-contained HTML comparison organizer with a Venn
diagram and a readable three-region equivalent at phone width.
Source A: [paste original or permitted text]
Source B: [paste original or permitted text]
Features to compare: [enter]
Keep the source texts visible and unchanged. Use A only,
Both, B only and a separate Not established category.
A feature belongs in Both only when both sources support it.
Missing information is not proof of absence or agreement.
Include labeled fixed feature cards, a destination control
and Check placement. Explain each authored card's placement
with its source lines. Changing the card or destination must
clear stale feedback. Include a worked comparison sentence
and a separate blank learner explanation for human review.
Do not score arbitrary writing or invent facts about the texts.
Use native controls, visible keyboard focus and text feedback.
Keep the sources and category labels legible at 360px without
horizontal overflow. Put all CSS and JavaScript in the file.
No external assets or data submission. State that typed work
is for the current session and ask before clearing it.
Return the complete HTML.
Test the generated organizer with one detail absent from both sources. Then change a source line and check every card that depends on it. A new notice may change several placements at once.
Keep the comparison labels precise
If a colleague reads “Materials” as a list of what to bring, open the HTML organizer in NOS and rename the label to “Supplies provided” in visual editing mode. The revised label now matches the line in both notices.
Check the amended label against both notices, then ask the learner to explain why “Free entry” still has no established placement inside the circles.