Highlighting can teach, or it can become visual noise
A passage with every other word highlighted is not helpful. A passage with no highlighting may hide the curriculum design. Highlighted reading works only when highlights communicate purpose.
The central distinction is:
Focus items are what the current lesson is teaching. Review items are what earlier lessons are bringing back.
Both matter. But they should not look or behave exactly the same.
The key principle:
Highlighting is a learning interface, not decoration.
Focus items deserve strong attention
Focus items are the new targets. They should be visible enough that the learner knows what the current deck is about.
Example passage:
Para completar el trámite, Laura tuvo que adjuntar un comprobante y esperar la resolución de su expediente.
Focus items might be:
trámite, adjuntar, resolución, expediente
The learner should be able to tap each item and see:
- base form,
- translation,
- part of speech,
- short usage note,
- sentence meaning,
- audio if useful.
Focus highlights should support deliberate learning.
Review items should be visible but lighter
Review items have already appeared before. Their role is reinforcement.
Example:
Laura revisó la fecha, preparó sus documentos y fue a la oficina.
If fecha, documentos, and oficina are prior-deck items, they might receive a lighter highlight. The learner can tap them if needed, but the interface should not imply they are the main new targets.
Review highlighting tells the learner:
This is not new, but it is worth recognizing again.
Cognitive load matters
Too many highlights make a passage unreadable. The learner stops reading and starts hunting colored words.
Design questions:
- How many focus items appear per paragraph?
- Are review highlights visually quieter?
- Can the learner turn layers on/off?
- Do highlights interrupt line spacing?
- Does tapping return smoothly to the reading position?
- Are repeated items highlighted every time or only first occurrence?
The goal is not maximum marking. The goal is guided reading.
Tap behavior should match item type
A focus item tap might show a richer note:
adjuntar
to attach/enclose
Verb. Common in forms and email.
Example: Debe adjuntar una copia del pasaporte.
A review item tap might show a lighter reminder:
fecha
date
A difficult review item can optionally expand. But the default should respect the learner's attention.
Scroll targets and return points
Reading interfaces often fail at navigation. If the learner taps a glossary entry and loses their place, the reading flow breaks.
Good behavior:
- tap highlight,
- note opens inline or in a panel,
- close note,
- return to same line,
- optional “show all focus items” list,
- optional scroll target from glossary to passage.
The interface should support close reading, not punish curiosity.
Review density should grow over time
Early passages should not overload the learner with review items. Later passages can include more review because the learner has a larger base.
A curriculum might progress:
- Deck 1: almost all items are focus.
- Deck 10: focus items plus a few review items.
- Deck 50: dense review across earlier domains.
- Deck 200: natural passages with many familiar items.
This creates a sense of cumulative literacy.
Highlights should fade as competence grows
A highlight that never disappears can become a crutch. Early in learning, visual support helps the learner notice forms. Later, the learner should begin recognizing them without signals. A good system can fade support gradually.
First reading: focus and review items visible. Second reading: focus visible, review hidden. Third reading: only missed items visible. Exam mode: no highlights. Remediation mode: highlights return for unstable items.
This keeps the interface from teaching dependency. The goal is not for the learner to become good at reading highlighted Spanish. The goal is to read Spanish. Highlighting is a scaffold, and scaffolds should be removable.
The system can also let the learner choose: show all, show current, show missed, or hide all. Serious learners appreciate control when the options reflect real pedagogy.
Example bank walkthrough
focus highlight
Visual marker for current deck targets.
Learner action: study these actively.
review highlight
Visual marker for prior-deck items.
Learner action: use them as spaced reinforcement.
glossary
Tap support.
Learner action: check meaning quickly and return to reading.
scroll target
Navigation anchor.
Learner action: move between item list and passage without losing context.
prior deck
Earlier curriculum source.
Learner action: treat repeated words as retrieval opportunities.
current deck
Current learning target set.
Learner action: focus effort on these items first.
Accessibility beyond color
Highlighting should not depend only on color. Some learners use grayscale printouts, dark mode, screen readers, or have color-vision differences. Focus and review items can be distinguished by more than hue:
- underline style,
- border style,
- icon or label,
- glossary grouping,
- tap behavior,
- typography weight used sparingly.
The design should also avoid turning highlighted text into low-contrast text. A beautiful highlight that reduces readability is a failed learning tool. Accessibility is not a secondary polish step; it is part of whether the reading interface actually teaches.
Remediation notes: highlighting is a scaffold that should eventually get out of the way
The repair for highlighted reading is to treat highlights as temporary guidance, not permanent decoration. Highlighting can direct attention to focus items and remind learners of review items, but too much color turns a passage into visual noise. A learner who sees every other word highlighted may stop reading and start scanning.
Focus and review items should differ in behavior, not only appearance. A focus item deserves a stronger affordance: tap for definition, part of speech, audio, example, conjugation note, or register warning. A review item can be lighter: tap for quick recall or prior-deck reference. If both behave the same way, the interface fails to teach priority.
The article should also add fading. Early in a deck, highlights help noticing. Later, the same item should appear with weaker support, then no support, then reappear in assessment. This prevents dependency. The learner’s target is not to become good at reading highlighted Spanish. The target is to read Spanish.
Accessibility matters. Highlight systems should not rely on color alone. Learners with color-vision differences, dyslexia, low vision, or small screens may need underline, weight, icon, spacing, or tap target adjustments. Dense line spacing can make highlighted passages harder to read. A beautiful interface that slows reading is a bad learning tool.
Review density should be managed by curriculum stage. Beginner passages need fewer highlights because the learner’s working memory is fragile. Advanced passages can include more review because the learner has a larger base. But even advanced learners need coherent prose. Highlight density should follow pedagogical load, not the product team’s desire to show coverage.
Production target: design highlights with a fade plan: new, review, weak review, unhighlighted, assessment. For each passage, count not only highlighted items but the learner’s likely cognitive load. The best highlight is the one that helps today and becomes unnecessary tomorrow.
Suggested interactive module: highlight-layer mockup
A strong tool for this article would let designers test highlighting choices.
Suggested functions:
- Layer toggles: focus only, review only, both, none.
- Density meter: highlights per paragraph.
- Tap preview: focus note vs review note.
- Repeated-item rule: highlight first occurrence or all occurrences.
- Glossary link: item list jumps to passage line.
- Cognitive-load warning: too many highlights in one view.
- Accessibility check: contrast and non-color markers.
Final rule
Highlighting should teach attention.
Mark focus items as current targets and review items as returning knowledge. Keep the visual system quiet enough for real reading. A highlight is valuable only when it helps the learner read, remember, and return.