Sci method and experimentation Flashcards
What are the eleven principles of experimentation?
Planning and design, safety procedures, random selection, large sample size, control group, double-blind testing, change one variable at a time, measure changes, analyse the results, state possible sources of error, repeat the experiment
What is planning and design?
.
What are safety procedures?
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What is a control experiment?
.
What is the sample size?
.
What is random selection?
.
What is replication?
.
What is double-blind testing?
.
What are sources of errors?
.
What is an experiment?
An experiment is a controlled test where only one variable is changed at a time
What is the rule regarding variables?
Only one variable should be changed at a time
What is the name of the variable that is changed?
The independent variable
What variables are changed?
The independent variable is changed by the experimenter.
What is the dependent variable?
The variable affected during the experiment (responding)
What is a constant?
The part of an experiment that does not change
What are controlled variables?
Variables which could change but are not allowed to
What are the two parts to an experiment?
The control group and the experimental group
What is the control group part of the experiment?
An experiment carried out alongside the main experiment in which nothing is changed or influenced which is then compared to the experimental group to ensure any changes are caused by changing the independent variable
What is the experimental group part of an experiment?
The experimental group is the main experiment in which the independent variable is changed by the experimenter and nothing else
What is the goal of experiments?
Prediction
Give an example of an experiment, it’s parts and whether it’s good and problems with it
An example of an experiment
Observation: It has been suggested that large daily doses of Vitamin C protect against the common cold virus.
Hypothesis: Vitamin C protects against the common cold virus
Experiment design: Ten adult males in their mid twenties who are friends of the investigator were chosen to test the possible value of vitamin C.
5 of them were given 3000mg of vitamin C a day; the other 5 were given a placebo.
The control group are the ones with the placebo
The experimental group are the ones with the vitamin c.
Problems with experiment design
All males
All mid twenties
All friends
Not a large enough sample
What should a good experiment have?
Only one variable, a large number of samples, random selection, repetition and double blind testing
