experimental terms

Question 1

hypothesis

Answer 1

your prediction of how the experiment will come out, based upon a theory

Question 2

population

Answer 2

all cases in a study; group from which samples are drawn. If you were studying teen driving for instance, teens would be your population; the specific teens you studied would be your sample. Ideally, all the teens would have an equal chance to be subjects to have a perfect random sample, but if the group you choose from is representative of the population, (meaning same proportion of gender, ethnicity, age, etc.) and all of those have an equal chance of being chosen, then you have a random sample

Question 3

random sample (sometimes just called sample)

Answer 3

the group you are doing the actual experiment on. They should all have had the same chance of being selected from the population.

Question 4

random assignment

Answer 4

the way in which you assign members of the random sample to the control or experimental group. Again, each member of the random sample should have an equal chance of being selected to each group. Try to keep all things equal. Wait until everyone is there and randomly select them

Question 5

subject

Answer 5

the person you are doing an experiment on; a member of the radon sample who has been randomly assigned

Question 6

operational definition

Answer 6

a statement of the procedures used to define research variables. Spell out what you are comparing and how you are going to measure and compare the dependent variable

Question 7

independent variable

Answer 7

The experimental factor that is going to be manipulated or changed. You will compare the results of this fact to a baseline or control group on which the variable was not down (called a between subjects design), or you may compare the group in a before-and-after scenario, in which their original state or scores act as your baseline or control group (within subject design).

Question 8

experimental group

Answer 8

the group being experimented on or acted upon by the independent variable.

Question 9

control group

Answer 9

group compared to the experimental group to see if any change has occurred because of the independent variable

Question 10

dependent variable

Answer 10

behavior or mental process that is being tested; the behavior or mental process that changes because of age introduction of the independent variable. The results of the experiment are compared to the behavior or mental process before and after, or against the control group of the dependent variable

Question 11

results

Answer 11

the outcome in quantitative or measurable behavioral terms comparing the dependent variable before and after

Question 12

discussion

Answer 12

your assessment of the experiment based on age results. Did it prove our hypothesis? Did you discover control problems? What further study might be needed?

Question 13

control of possible confounding variables

Answer 13

steps you take to make sure your random samples are as identical as possible and that the environment in which they are tested are as similar as possible

Question 14

confounding variable

Answer 14

uncontrolled variables that affect the control group and experimental group affecting your results. It could be things like time of day being different, using a male voice in one group and a female in another, and other distracting circumstances

Question 15

double blind as a control for experimenter bias

Answer 15

if you’re asked to control for experimenter bias, you can’t go wrong by using a double blind technique, wherein neither the experimenter nor the subject know who is in the control group or experimental group so that they will not sway the results. The experimenter may know the intent of the study. To be even purer, you could use a tester who doesn’t even know what he/she is testing for

Question 16

Z-score

Answer 16

• known as a Standard Score, is a statistic that tells us where a score lies in relation to the population mean. A positive ___ means that the score is above the mean, while a negative ___ means that the score is below the mean. In addition, it tells us how far the score is from the mean. It is a very useful statistic because it allows us to compare two scores coming from two different distributions.
• between -3 and positive 3
  ex. you get a 80% on a test and the mean (average) is 95 and the composite score is 5. you would do 80-95/5, which is -1. so, your z-score is -1.

Question 17

mean

Answer 17

the sum of a list of numbers, divided by the total number of numbers in the list

Question 18

median

Answer 18

“middle value” of a list; the smallest number such that at least half the numbers in the list are no greater than it. If the list has an odd number of entries, it is the middle entry in the list after sorting the list into increasing order. If the list has an even number of entries, it is equal to the sum of the two middle (after sorting) numbers divided by two

Question 19

mode

Answer 19

for lists, it is the most common (frequent) value. A list can have more than one. For histograms, it is a relative maximum (“bump”)

Question 20

standard deviation

Answer 20

tells how spread out numbers are from the average; calculated by taking the square root of the arithmetic average of the squares of the deviations from the mean in a frequency distribution