Experimental Research free essay sample

This paper explores the experimental research method and specifically the experiment conducted by Professor Smith, a Psychology professor who has a hypothesis that Vitamin E improves memory, to determine the flaws in her experiment. In the process, the paper also clearly explains the various key factors which determine the outcome and accuracy of the method of experimental research, such as dependent variables, independent variables, experimental groups, and control groups. This paper examines the factors that render Professor Smith’s experiment as flawed, and finally attempts to redesign an experiment to successfully test the effects of Vitamin E on memory. Experimental Research and The Key Components of A Successful Experiment Experimental research is the scientific method used by psychologists to answer some important cause and effect questions about behaviour and other phenomena of interest. Experimental research investigates the relationship between variables by intentionally causing a change in one variable in a situation, and then studying the effects of that change on other aspects of the situation ( Feldman amp; Dinardo, 2012 ). We will write a custom essay sample on Experimental Research or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The independent variable in experimental research is manipulated by the researcher and is the variable whose effects the researcher attempts to investigate. The dependent variable in experimental research is the response or effect acquired as a result of the independent variable. Participants in experimental research are always divided into two groups, an experimental group and a control group. The experimental group is the group participating in an experiment which receives a treatment in order to assess the effects of the independent variable on that group, while the control group receives no treatment. The experimental group’s behaviours or actions in a situation are manipulated by the independent variable, while the control group is not influenced in any way by the independent variable being investigated. The control group has to be equal in all aspects to the experimental group except for the presence of the independent variable, which would differentiate the behaviours, events, or other characteristics of the two groups. This is done in order to accurately investigate the true effects of an independent variable. Professor Smith’s Experiment Professor Smith conducts an experiment to test her hypothesis that Vitamin E improves memory. Before a quiz in her class, she provides half the class with lemonade juice-boxes and Vitamin E, which is the independent variable in this experiment. The remaining half of the class aren’t given anything. Professor Smith divides the class into two groups of twenty students. The first twenty students to arrive are made to sit in the front of the class, this is the experimental group who receive the independent variable, Vitamin E. The other twenty students are made to sit in the back, this is the control group who receive nothing. She then gives them a quiz. Once it is completed, she discovers that the experimental group who received Vitamin E scored an average of 3 points higher than the control group who received nothing. The score on the quiz is the dependent variable of this experiment, and the factor being measured in order to determine the effects of Vitamin E. Flaws of Professor Smith’s Experimental Design and Conclusion A set of meticulous guidelines need to be followed in order to conduct an experimental research and achieve an accurate result or conclusion. According to Abdi ( 2009 ), a researcher must impose controls to ensure that changes in the independent variable are the only things that affect the dependent variable in an experiment in order to ensure it’s validity. The first flaw with Professor Smith’s experimental design is that the controlled group received nothing while the experimental group received the Vitamin E and lemonade juice-boxes, which creates a psychological inequity. This could easily have had a demoralizing effect on the mental state of the control group and an encouraging effect on the experimental group, which would decrease the accuracy and validity of her findings as other factors beside the independent variable could have affected the dependent variable. Another flaw with her experimental design is the division of the experimental group and the control group into two seperate sections, creating a social inequity, specially as the first half of the students were allowed to sit in the front and the latter half were made to sit in the ramaining half of the class in the back. This could have created a sense of expectancy in the experimental group and compelled them to try harder, while the control group might have assumed they weren’t expected to do well and as a result not strive enough to succeed. According to Feldman and Dinardo ( 2012 ), one of the factors that distort how the independent variable affects the dependent variable in an experiment is participant expectations. The participants in Professor Smith’s experiment were aware of their assigned groups, which could have raised or lowered their expectations, depending on the group to which they were assigned. Finally, the flaw with Professor Smith’s conclusion is that the experiment was conducted to test her hypothesis that Vitamin E improves memory, but her conclusion was that Vitamin E makes one smarter. Aside from that, Professor Smith was also aware of the group to which a particular participant was assigned and this could have had an effect on her preference and partiality towards the participants. The conclusion, aside from being inaccurate, was irrelevant to the hypothesis. Redesigned Experiment In order to test the effects of Vitamin E on memory the experiment can be conducted with some necessary amendments to acquire an accurate dependent variable and a valid conclusion. First, in order to control the bias, there would need to be a placebo control group, which entails administering a fake independent variable to the control group. By doing this and maintaining equality between the experimental and control group in terms of resources provided, whether it’s a lemonade juice-box, controls would be imposed to ensure that changes in the independent variable are the only things that affect the dependent variable, and thus increase the validity of the experiment ( Abdi, 2009 ). Another important amendment needed would be randomly seating the two groups by using a method called the double-blind procedure, in which neither the researcher nor the participants would be aware of the particular group to which a participant elongs. Randomly seating the participants all around the classroom and not being aware of the group to which a participant is assigned would create equality, thus eliminate the possiblility of expectations distorting the dependent variable. Conclusion Experimental research depends on a few key components in order for it to be successful. A researcher must always impose stern controls to ensure tha t the only change affecting the dependent variable is the independent variable whose effects are being investigated.