To accompany Lesson 1.4 of Beginning Statistics. © 2013 Hawkes Learning Systems/Quant Systems Inc.
BIAS is favoring of a certain outcome in a study.
RESEARCHER BIAS – when a researcher influences the results of a study.
RESPONSE BIAS – when a researcher’s behavior causes a participant to alter his response, or when a participant
gives an inaccurate response.
SAMPLING ERRORS
Dropout – a participant who begins the study but fails
to complete it.
Sampling Bias - Poor sampling frame, the sample does
not accurately represent the population being studied.
Participation bias – when there is a problem with
either the participation, or lack thereof, of those
chosen for the study.
Nonresponse bias – when there is alack of
participation in a self-selected sample from certain
segments of a population, when a person refuses to
participate in a survey, or when a respondent omits
questions when answering a survey.
NON-SAMPLING ERRORS
Processing error – a typo, 1+1=3, etc.
Lying, or faulty memory
Non-adherents – subjects who stray from the
directions they were given.
Confounding variables – factors that influence the
results o fthe study that the researchers did not, or
count not, account for.
ErrorsAndBias.docx 1/7/2016 7:27 PM DRS