Notebook AtlasSURG0002 · Research methods: go to the course map

AtlasFoundations · start here

Averages and spread, by eye

  1. What is data?
  2. Averages and spread, by eye

Fig. 1

Days to full closure of splinted excisional wounds in 9 mice under a hydrogel dressing (days)

Fig. 1. A dot strip of 9 mice (days to full wound closure) resting on a seesaw. It balances at 16.00 days, the balance point (mean); the middle mouse sits at 15.00 days (median). They run from 12 to 27 days.

Balance point (mean)
16 days
Middle value (median)
15 days
From smallest to largest
12 to 27 days

Distribution Lab · First look

every mouse is where it was measured

Level 1 · First look · Foundations (ext)

Pick a typical value and say how spread out the values are, by eye.

Find a typical value (mean or middle value) and describe spread by eye, and see why one extreme value moves the mean but not the median.

ext A Foundations primer: written for beginners, not from the slides.

  1. Typical value (the step you are on)

    A family's shoe sizes cluster around one size; most mice heal in about two weeks.

    Like a family’s shoe sizes, the healing times bunch around one value: most of these 9 mice closed their wounds in about two weeks, and the middle one took 15 days.

step 1/4