15 - hypothesis testing Flashcards
what is the scientific method
“[…] a method for finding about about the world based on the
generation of hypotheses and the testing of predictions derived
from those hypotheses.”
Robert Dunbar, 1995
observation - hypothesis - test predictions - conclusions
theory, hypotheses and predictions
Theory = a coherent explanation for many observations
Hypothesis = a proposal about how a phenomenon works
Prediction = what we should observe if our hypothesis is true
what makes a hypothesis scientific
- Testable: with empirical data (i.e. from observations of the external world)
- Falsifiable: there must be some possible evidence that could invalidate it
- But we accept scientific hypotheses cannot be proved with 100% certainty
limitations of the archaeological record
Taphonomic biases: only hard, non perishable artefacts survive long periods e.g. vast majority of modern Hazda material culture
Dating uncertainty: disagreements common, consequences large
difficulties of interpretation: meaning opaque without cultural referents e.g. eggshell engravings: social identity markers or iconic representations?
comparative method
- tests hypotheses with comparative data, phylogenies and statistical models
- commonly used to date the origins of a trait and test adaptive hypotheses
limitations of comparative method
many assumptions, built upon incomplete data
often do not incorporate fossil data, assume present extrapolates to past
experimental evidence
I.e. tests of hypotheses under controlled conditions, with modern participants
experiments
aim to test causing hypothesis by isolating variables
independent variable - change A and hold everything else constant
dependen variable - see what happens to B when we change A
usually includes a control: gold standard in medical research is randomised control trials
limitations of experiments
ecological validity usually low (i.e. tasks highly artificial)
ecological validity trade offs against experimental control
Experimental participants often WEIRD, not representative of ancestral humans.
modern hunter gatherers cannot be used to represent ancestral humans either
what else can we do
other approaches possible e.g. simulations
useful for studying processes not easy to observe, but make many assumptions
multiple complementary lines of evidence helpful for evolutionary hypothesis as we have to rely on incomplete data, assumptions and indirect tests
