Speak up! 9. Say It Visually: Designing Effective Slides

9. Say It Visually: Designing Effective Slides

visuals

Visual aids—like slides, charts, diagrams, and videos—can strengthen your message, clarify complex ideas, and keep your audience engaged. But only when used effectively.

In this section, you will learn how to:

  • Choose and design visual aids that support—not distract from—your message

  • Apply principles of layout, contrast, simplicity, and readability

  • Avoid common mistakes such as overloading slides, reading word-for-word, or using visuals that confuse instead of clarify

You will practice integrating visuals into your technical presentations in a way that makes your  ideas clear, memorable, and professional.

Using Graphs in Presentations: What to Use and When

  Line graph

  Bar graph

  pie chart

  Flow chart

  Area chart

  Scatter Plot

The Importante of Font and Colour in Visual Aids

  Font: Clarity Comes First

Use clean, sans-serif fonts like Arial, Calibri, or Helvetica for readability.

Avoid overly decorative or script fonts—they may look interesting but are hard to read quickly.

Size matters: Body text should be at least 24–28 pt. Titles or headings should be 36–44 pt or larger.

Use one or two fonts consistently (e.g., one for headings, one for body text).

Avoid ALL CAPS for long blocks of text—it reduces readability.

Use bold or color, not underlining, to emphasize.

Colour

  Guide the Eye and Create Contrast

High contrast between text and background is key: dark text on a light background or light text on a dark background.

Use color to highlight important points, differentiate categories, or signal transitions.

Avoid using red and green together—some audience members may be colorblind.

Stick to a simple, consistent color palette (2–3 main colors).

Use blue, dark gray, black for text; reserve bright colors (like orange or yellow) for emphasis only.

Make sure text is clearly visible from the back of the room or on all screens.

WHY ARE THESE POORLY DESIGNED SLIDES?

Poorly design slide 1

1. Overcrowded Text

  • The slide includes too many bullet points, each with multiple clauses and subpoints.

  • There’s no visual breathing room, making it difficult for the audience to read or retain any of the information.

2. Tiny, Dense Font

  • The text is too small and packed closely together.

  • It lacks a readable hierarchy—everything is the same font weight and size.

3. Spelling and Grammar Errors

  • Multiple words are misspelled (e.g., “analasis,” “modugl,” “scse,” “difinitin”).

  • This damages credibility and distracts from the content.

4. Ineffective Use of Visuals

  • A pie chart is present but has no labels, title, or clear purpose.

  • It’s unclear how the chart relates to the bullet points.

5. Distracting Color and Layout

  • The bright red title on a pale blue background is harsh and jarring.

The layout lacks alignment and feels unbalanced—text and visuals are just placed arbitrarily.

6. No Focal Point

The audience doesn’t know where to look: text, pie chart, or title?

There’s no visual hierarchy or emphasis.

 

Poorly designed slide 2

1. Too Many Colors (and Clashing Ones)

  • The bright neon green background combined with red, orange, yellow, blue, white, and black text overwhelms the eye.

  • Some colors (like red on green or yellow on green) have very low contrast, making them hard to read, especially for colorblind viewers.

2. Inconsistent Font Styles

  • The slide mixes underlined, bold, italicized, and colored text, creating a cluttered, chaotic appearance.

  • There's no hierarchy—it's not clear what’s a title, a description, or a category.

3. Poor Alignment and Layout

  • The spacing between app logos and text is inconsistent.

  • Text and icons are not properly aligned, making the slide feel unbalanced.

  • The vertical alignment is off; some app descriptions look "floating."

4. Lack of Visual Hierarchy

  • Every app and text block has equal visual weight—there’s no clear focus.

  • The viewer doesn't know where to look first, or what’s most important.

5.  Font Readability Issues

  • Small text in light colors (e.g., yellow on green) is very difficult to read.

  • Some phrases like “IdeThoughtsas” appear to have typos or awkward formatting.

Poorly designed slide 3

1. Overly Complex and Confusing Flow

  • The diagram includes too many intersecting lines and arrows going in multiple, unclear directions.

  • It’s difficult to understand where the process starts, what each path means, or how to follow the flow logically.

2. No Labels or Context

  • All boxes say only “Sample Text,” which gives no indication of content or purpose.

  • Even though some diamonds might represent decisions (based on shape), there's no meaningful information for the viewer.

3.  No Visual Direction or Hierarchy

  • There's no consistent flow direction (e.g., top-down or left-right).

  • Some arrows go backward, diagonally, or loop without clarity, making it visually chaotic.

4. Uniform Design with No Emphasis

  • All boxes are the same size, color, and font, with no distinction between actions, decisions, or outcomes.

  • There’s no visual hierarchy to guide the eye or emphasize key points.

5. Cognitive Overload

  • Too many elements are crammed into one visual with no white space, making it mentally exhausting to process.

  • Instead of simplifying the message, the slide creates confusion and frustration.

 

Poorly designed image 4

1.  Low Color Contrast

  • The yellow text on a magenta background is visually harsh and difficult to read for many people, especially those with visual impairments or color sensitivity.

  • It may cause eye strain and makes the text harder to focus on from a distance.

2. Text-Heavy Format

  • The slide relies only on bulleted text, without any visuals, icons, or illustrations to support comprehension or provide variety.

  • It resembles a verbal script, rather than a visual aid that complements the speaker.

3. No Visual Hierarchy

  • All the bullet points are the same size and weight as the title, and all points look equally important.

  • There's no emphasis or structure to help guide the audience’s attention.

4. Lack of Visual Balance

  • The slide has a centered block of yellow text with no margin or spacing, which feels visually dense.

  • There's no spacing between bullets, making it harder to scan.

5. No Engagement or Visual Cues

  • There are no diagrams, images, or visual context—nothing to help the audience retain or understand the information visually.

  • Slides like this often encourage reading aloud, which weakens the speaker’s delivery.