Essay 1996 #2 – Kayla Lett
Sampling
Sampling is the process by which people in the population are selected to participate in the
experiment. Professor Jackson’s sample was her introductory psychology class of approximately 100
students. Her sample is flawed because the participants were not randomly selected; therefore, the
sample is not representative of the population she wishes to study. To correct this, Professor Jackson
could have selected her sample by choosing every tenth number on a numerical list of her population.
Assignment of Participants
The assignment of participants occurs when the sample is divided into the experimental or
control group. Professor Jackson assigned the first fifty participants that arrived to the control group
when they arrived. The flaw in the assignment of participants in this experiment was that it was not
done randomly and participants did not have an equal chance in being in the control or experimental
group. To correct this, a numerical list of the sample could have been used to randomly assign the
participants to each group.
Dependent Variable
The dependent variable is the variable being observed and measured in an experiment.
Professor Jackson’s dependent variable was the professional goal/strength of achievement motivation
of the participants after they had completed a puzzle. The dependent variable is flawed in this
experiment because Jim and Professor Jackson can use the 7-point rating scale differently, therefore,
the results from both groups could be inconsistent. To correct this flaw, a list of career choices and
corresponding achievement ratings should be given to each of the score recorders so that careers will
have consistent scores in both experimental and control groups.
Control for Experimenter Bias
Experimenter bias occurs when the experimenter favours a particular outcome and will
potentially set up the experiment or influence it in such a way that the favoured outcome is proven. In
this experiment, Professor Jackson neglected to control for experimenter bias. The flaw was that
Professor Jackson collected scores herself, and did not use the double blind procedure, a process by
which the participants and observers do not know what group they are a part of. To properly control for
experimenter bias, Professor Jackson could have randomly selected/assigned participants, used the
double blind procedure, and stayed out of the score collecting process.
Control of Confounding Variables
Controlling for confounding variables is the process by which variables that could potentially
ruin the experiment are eliminated from the population before subject selection occurs. Professor
Jackson allowed all of her psychology class to participate and did not control for confounding variables.
This is flawed because people who could not fully participate in the experiment, (due to health issues,
for example) were allowed in the experiment. To correct this, Professor Jackson could have eliminated
blind people from the population because they could not complete puzzles.