How to Annotate Lecture Slides Before, During, and After Class

Annotating lecture slides works best when each note adds something the deck does not already say: an explanation, example, condition, question, or connection. Keep that addition beside the relevant slide so you can distinguish the lecturer's point from your own interpretation later.

Use three passes: prepare space before class, capture missing meaning during class, and verify the additions afterward. You do not need to rewrite every bullet or finish every gap in one sitting.

Set up a small key and identify the deck

Record the course, lecture date, and deck version on the first page. If the lecturer posts a revised file, keep the earlier version until your annotations are transferred and checked.

Use a small key:

Mark	Meaning	Useful annotation
!	Emphasis	Why the lecturer highlighted the point
+	Added explanation	Meaning absent from the slide text
EX	Example	What the example demonstrates
?	Unresolved gap	The exact question to investigate
↔	Connection	Another slide, reading, or earlier idea

Next to a substantial addition, write where it came from: class notes, an authorized recording timestamp, a reading page, or your own tentative interpretation. The symbol describes the note's purpose; the source label describes its evidence.

Before class: create places for explanations

Carnegie Mellon University's lecture-note guidance recommends reviewing the day's topic, previewing reading, and revisiting prior notes. Apply that preparation to the deck:

1. Read the title, section headings, and learning objectives.
2. Mark unfamiliar course terms without replacing them.
3. Leave space around diagrams, formulas, and sparse slides.
4. Write one question that connects this lecture to the previous one.
5. Check which materials and AI uses your course permits.

A short preview is a planning choice, not a guarantee that a dense lecture can be prepared in a fixed number of minutes. If your main task is discovering gaps before class, see the lecture-preparation guide.

During class: capture the addition beside its anchor

Barnard College's note-taking guide recommends reviewing available slides and writing on them while focusing on the lecturer's meaning. Use brief phrases rather than trying to transcribe every sentence.

Prioritize the reason for a worked step, a limit on a rule, a contrast between similar concepts, or the explanation of a visual. Preserve negations such as “not,” and conditions such as “only when.” If you miss something, leave a question and keep listening.

When slides arrive after class, use topic headings and a distinctive phrase as temporary anchors. Attach the notes to the correct slides when the deck is available; do not assign a guessed slide number and forget to check it.

Keep an annotation evidence table

This manual table is useful when additions accumulate across a deck. It is not an automatic Notoo feature.

Slide and version	Addition	Evidence	Status	Next action
Slide or section anchor	Explanation, example, or condition	Class note, permitted timestamp, reading page, or my inference	Captured / checked / unresolved	Check, ask, or turn into a recall prompt

“Captured” means you wrote it down. “Checked” means you verified it against the relevant source. Keep uncertain recollections unresolved even if the prose sounds plausible. A classmate can help locate a gap, but check important course claims against the lecture or assigned material.

Teaching example: an exception gets lost

This is a fictional lecture example, not a real course excerpt or product test.

An imaginary slide says: “Use the course model under the stated assumptions.” During class, the lecturer adds: “Do not apply this version when the boundary condition changes.” Your hurried note becomes: “Apply the model when the boundary changes.”

The missing negation reverses the instruction. A polished rewrite could preserve that mistake.

Repair it in the evidence table:

• Anchor: the model slide and deck version.
• Captured addition: a condition about when the model applies.
• Check: the relevant class note or permitted recording segment.
• Corrected note: this version excludes the changed boundary condition.
• Unresolved item: which alternative method the course expects in that case.
• Recall prompt: state the condition under which this model should not be used.

Do not invent the alternative method just to close the row. Keep the question for the tutor if the source does not answer it.

After class: repair, explain, and test

CMU's guide recommends revisiting notes, explaining material in your own words, and marking uncertainty. Barnard also suggests filling missing information and attempting practice questions before looking at the notes.

Use a manageable pass:

1. Find rows marked unresolved and check the highest-priority ones.
2. Add the source location when a gap is resolved.
3. Write one takeaway for each topic group.
4. Close the deck and explain one idea, redraw one visual, or attempt one problem.
5. Compare the attempt with the source and record what needs another review.

Time-box the pass if useful, then carry unfinished rows forward. Do not erase question marks to make the deck look complete. For a visual that needs more than a text annotation, follow the diagram-study workflow.

Use AI for a draft structure and retain your evidence

Notoo's slides-to-notes workflow accepts PPT, PPTX, and PDF decks and drafts notes from readable material. The official page warns that sparse text, diagrams, and missing spoken explanations need checking.

Use that draft as a topic outline. Compare it with the deck and your additions. Do not assume that handwriting, slide comments, speaker notes, or an annotation application's layers were captured merely because the file uploaded successfully.

A bounded instruction for an approved AI workflow is:

Organize the readable material by topic. Keep course terms. Mark missing explanations and uncertain visual details as gaps. Do not treat my questions as facts or invent what the lecturer said.

The evidence table remains a manual record. Add spoken details only from sources you actually have permission to use.

Copy this before-during-after checklist

Course / lecture / deck version:
Before: main question, unfamiliar term, previous-topic connection
During: ! emphasis, + explanation, EX example, ? gap, ↔ connection
Evidence: slide anchor plus note / timestamp / reading location
After: corrected addition, checked source, unresolved question
Recall: one explanation / drawing / problem attempted with notes closed
Next review: what still failed and which source to revisit

For international students, put the official course term first, followed by a plain-English gloss and an optional translation. Keep abbreviations consistent. If a translation removes a condition or changes a technical meaning, repair it before making practice cards.

Make the next deck easier to review

Choose one topic group, attach your additions to stable slide anchors, and check one unresolved condition before converting it into a study prompt. Keep the deck as the source and your annotations as a traceable layer of meaning. For a draft outline you can check alongside it, upload a permitted deck to Notoo.