It's easy to fall into the “cover all your bases” trap—adding every point that might help. But more isn’t better if some of those points are weak. Without realizing it, you lower the overall strength of the message. That’s the dilution effect. In today’s edition: a simple test to help your strongest ideas stand out.

When we hear a list of points in a presentation, we don’t judge each one on its own. We form a quick, overall impression—almost like averaging them.

So if you lead with a strong point, then follow it up with a few that are “just okay,” your audience doesn’t think, “Wow, three solid reasons.”

They think, “This is… fine?”

The weaker points pull the stronger ones down. Psychologists call this the dilution effect. We’re “cognitive misers”—wired to “spend” the least amount of mental effort. So instead of carefully weighing each point. We shortcut it. We average.

This is a problem, because most presenters instinctively go in the opposite direction. They think: “The more reasons I give, the stronger my case. Even if some are just filler, at least I’ve got one killer argument in there.”

But in practice? More only helps if every point is strong.

Today, we're looking at the science behind the dilution effect—and how to spot (and cut) weak points before they water down your pitch.

The science behind the dilution effect

The dilution effect comes from research in cognitive psychology (starting in the 1980s). The basic idea is simple:

When people are given a mix of strong, relevant details (diagnostic) and weak, irrelevant ones (nondiagnostic), they don’t ignore the weak info—they average it in.

That weak info dulls the impact of the strong.

In a classic study (Tetlock & Boettger, 1989), participants evaluated a job candidate:

• Group A heard strong traits: “intelligent,” “emotionally stable.”
• Group B heard the same traits plus irrelevant ones: “likes music,” “has a younger brother.”

Group B rated the candidate less suitable—not because of negative info, but because the added fluff diluted the good stuff.

These studies weren’t about presentations. But the mental setup is the same:

• Your audience is forming a judgment (Do I trust this? Does it make sense?)
• You’re presenting a sequence of info—often without signaling what matters most
• And they’re not weighing each point individually. They’re averaging.

How to spot and cut weak points in your presentation

Even thoughtful presenters fall into the “more is more” trap—adding extra points to sound thorough. But if they’re not all pulling weight, you’re diluting your case.

Here’s a simple two-part filter that helps you keep only what strengthens your case.:

1. Forced Ranking Test

Forced ranking = strict order of importance. No ties allowed.

• List your main points—key messages, arguments, or slides.
• Rank them based on how much they move your audience toward your goal.
  Ask: If they only remembered one thing, what should it be? What’s second? Third?
• Assign clear ranks: #1, #2, #3...
• Keep only the top 3–5.
  Everything else? Cut it or fold it under a stronger point.

2. Friction Test

Now run each remaining point through this test. It catches things that still might confuse, distract, or create resistance.

• Does this reduce confusion?​
  If not → Cut or rewrite.
• Does this reduce resistance (doubt, disbelief, disinterest)?
  If not → Reframe or drop it.
• Does it add drag?​
  (Drag = anything that slows understanding or makes your talk feel longer)
  If yes → Condense or absorb it.

Wrap-up

It’s hard to cut points that feel technically true, responsible, or contextually important. So even if a point doesn’t move the needle, it feels wrong to cut—because we overvalue completeness and undervalue focus.

But remember, the dilution effect doesn’t care how well-intentioned your extra points are.

The Forced Ranking + Friction Test helps you catch that before it happens—by separating what feels worth saying from what actually drives your message forward.

Use it to protect your strongest points. Because in high-stakes communication, one diluted message can cost you the decision.

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Until next week,
Meghan
Founder, The Good Deck

p.s. If someone you love is out there adding bullet point #27... intervene and send them this email. Their audience will thank you.