PAG Key terms Flashcards
what are the key factors needed for a good experiment?
precision
repeatability
validity
accuracy
precision
results which do not vary from the mean
what type of error leads to a decrease in precision?
random error
repeatability
whether the practical, if repeated by a different person using the same method and equipment, would achieve the same results
validity
are the control variables being controlled?
accuracy
you want the results to be as close to the real answer as possible
what are the main factors in designing an experiment?
variables
controls
repeats
sample size
what is the independent variable?
the one you are changing
what is the dependent variable?
the one you are measuring
it is DEPENDENT on the other variables
why is it important to control all the other variables?
you only want your independent variable having an effect on the dependent variable
what are the two types of control?
positive
negative
negative control
used to check if the independent variable is affecting the dependent variable
have no effect on the experiment
positive control
used to show what a positive test result would look like
why are repeats taken?
taking several measurements and calculating a mean allows you to reduce the effect of random error
identify any anomalies
MAKES IT MORE PRECISE
the larger the sample size
the less likely a result is due to chance
