Experimentation 3.2 Flashcards
what does validity relate to?
variables that are controlled so that any measured effect is likely to be due to the independent variable
what can variables be?
continuous os discrete
what does reliability relate to?
the confidence in the data and obtaining consistent values in repeats and independent replicates
what does accuracy relate to?
how close to the true value data, or means of data sets, are
what does precision relate to?
how close measured values are to each other
what is a pilot study used for?
- to help plan procedures
- assess validity
- check techniques
- it is integral to the development of an investigation
what does a pilot study allow?
the evaluation and modification of an experimental design
what can the use of a pilot study ensure?
-an appropriate range of values for the independent variable
- can help establish the number of repeat measurements required to give a representative value for each independent datum point
what is the independent variable?
the variable that is changed in a scientific experiment
what is the dependent variable?
the variable that is being measured as the results of a scientific experiment
what do experiments involve?
the manipulation of an independent variable by the investigator
what is the experimental group compared to?
a control group
what is a simple experimental design?
one in which there is one independent variable
what is a multifactorial design?
has more than one independent variable or a combination of treatments
what happens if investigators use experimental groups that already exist?
there will be no truly independent variable
what does the control of laboratory conditions allow?
simple experiments to be conducted more easily than n the field
what are drawbacks?
findings that ay not be applicable to a wider setting
what are observational studies good at detecting?
correlation
what are observational studies not good at determining and why?
causation as they do not directly test a hypothesis
what is not being directly controlled by the investigator for ethical or logistical reasons in observational studies?
the independent variable