---
title: "designing-studies"
aliases: 
tags: 
- info203
---

Need to be more specific than "Do you like my interface". Need to avoid experimenter bias

# Terms
- **Comparison:** What is good
	- "Yark stick"
- **Baserate:** how often does Y occur
	- requires measurin Y
- **Correlation:** Do X and Y co-vary
	- Requires measuring X and Y
- **Causes:** Does X cause Y
	- Requires measuring X and Y and manipulating X
- **Manipulations:** Indepenedent variables
- **Measures:** Dependent variables
	- e.g., task completion time, recall, accuracy, emotional response
- **Precision:** Internal Validity
	- remove confounding factors
	- large sample size
- **Generlisability:** External Validity
	- does this apply in the real world

# Strategies for fairer comparisons
Two main things differ between prototype and Production: Fidelity (how "polished the design is", Approach (the actual design)

- insert your new approach into the production setting
- recreate the production approach in you new setting
- scale down so youre just looking at a piece of a larger system
- when expertise is relevant, train people up

## Bad example
![iphone keyboard study](https://i.imgur.com/Gmski8F.png)

manipulation: input style
measure: words per minute
external validity: not so much

benefits and drawbacks
- not a fair example: novices vs experts
- are the results significant

## Good example
manipulation: input style
measure: words per minute and error rate

![speed](https://i.imgur.com/RvBVWt2.png)
![errors](https://i.imgur.com/GwYZOIA.png)
