Statistical methods Flashcards Preview

Laboratory Animal Science > Statistical methods > Flashcards

Flashcards in Statistical methods Deck (7):

What do you need to know before you start your experiment?

  • size of experiment
  • type of experiment
  • duration and sequencing of experiment
  • species, strains/stocks
  • adaptation
  • group sizes, number of groups
  • randomisation


Large group will affect the standard deviation how?

Larger group --> smaller SD


Why perform pilot experiments?

  • Logistis - setup of experimental protocol
  • effect size of treatment
  • variation
  • determine size of experiment (SD important)


name shapes for dose-response curves

  • linear response
  • nonlinear, monotonic response (slope is either positive or negative all the way)
  • nonlinear, nonmonotonic response (slope changes)
  • binary response (threshold; none at all, suddenly everything)


uni-variate statistics

  • variables are
    • independent
    • large numbers studies
  • Data tables are long and thin

can be analysed using ANOVA, t-test, linear regression, etc


today it is not uni-variate statistics, but

  • large number of variables
  • few number of animals
  • data tables are short and fat

This is done because

  • cost efficient
  • ethical
  • follow rules and regulations
  • other reasons

needs multivariate analysis, e.g. PCA


What happens when you use classical statistics on "short and fat" data? I.e. why do we need multivariate data analysis?

  • increased risk of false results (spurious results)
  • information is lost regarding dependent variables (co-variation)