Covariates used in the study
| Covariate | Encoding | Description | Summary |
|---|---|---|---|
| Age | Integer | Age in days | Mean = 61, SD = 4, 31–85 |
| Apparatus | Categorical | Experimental unit used | Groups = 4, size = 348–526 |
| Cage | Categorical | Cage in which animal was housed | Groups = 435–549, size = 1–7 |
| Cage density | Integer | No. of animals in a cage | Mean = 4.7, SD = 1.1, 2–7 |
| Experimenter | Categorical | Who performed the test | Groups = 2–12, size = 7–457 |
| Family | Categorical | Sibship of animal | Groups = 160–180, size = 1–52 |
| Hour | Categorical | Hour of the day test was performed | Groups = 1–11, size = 1–2307 |
| Litter | Integer | No. litter the animal came from | Mean = 2.2, SD = 1.3, 1–8 |
| Month | Categorical | Month test was performed | Groups = 12, size = 32–314 |
| Season | Categorical | Season test was performed | Groups = 4, size = 284–788 |
| Sex | Categorical | Sex of the animal | Groups = 2, size = 806–1293 |
| Study day | Integer | Day into study that test was performed (day 1 is Jan. 20, 2003) | Mean = 306, SD = 160, 1–621 |
| Test order | Integer | Order in which animal was tested that day | Mean = 2.8, SD = 1.4, 1–7 |
| Weight | Real no. | Body weight (g) at 9 wk | Mean = 23.9, SD = 4.2, 12–39.1 |
| Year | Categorical | Year of test | Groups = 2, size = 711–1517 |
“Encoding” refers to how a covariate was modeled statistically. For numerical covariates, the column headed “Summary” gives the grand mean and standard deviation over all phenotypes, followed by the minimum and maximum values observed for any given phenotype. For categorical covariates Summary gives the number and size of categories seen for a typical phenotype. For example, for phenotypes in which the experimenter covariate was present, there were between 2 and 12 experimenters who each recorded data for between 7 and 457 mice.