Abstract
This research report explores results from two sets of experiments conducted in the laboratory on sensitivity to weight and endeavors to determine through experiments how individuals discriminate against weights and their sensitivity to the application of a stimulus. In addition, it draws from experiments conducted by Fechner-Weber on the responses to weight thus establishing the relationships and validity between stimulus and perception.
The experiment conducted with standard masses and experimental cups to determine if perceived change in perception was noted by performing a one-way ANOVA tests and a detailed post-hoc test comparing 10 standard weights with each other. In addition, two academic papers reviewed on the effects of weight on sensitivity included the American Journal of Psychology.
Introduction
In an experiment conducted in college to determine how human beings discriminate against weight and the response to the application of a stimulus, an ANOVAs test was conducted and a detailed post-hoc test done with 10 standard weights. One’s response to a stimulus by discriminating between weights had the effect by the manner in which the weights had been were applied. Dinnerstein (2000) asserts that actual discrimination occurs when a stimulus was applied on an individual and actual perception noted for a change in the stimuli.
Literature review
The scientific study of sensitivity is vital in psychology. Fechner and Weber researched this quality in human beings through experiments they conducted to determine human response to the application of stimuli by classical methods now known as psychophysics, which emphasized on the need for accurate measurement of sensitivity.
These classical methods placed emphasis on determining the threshold, which discriminated between the level of stimuli and the sensitivity of an individual. The research results indicated that a highly sensitive individual required a low level of stimuli while a low sensitive individual required a high level of stimuli. Thus, an inverse relationship between sensitivity and the threshold value noted.
A threshold defined as “a level of stimulation that marks the entrance of an event into the observer’s awareness” sensitivity and Psychological Methods (p. 6). While an absolute threshold was the least amount of stimulus needed for a noticeable change in perception to occur while a just noticeable difference, (jnd) was the minimal difference in weight required for the participant to discriminate between stimuli, which can be a variation of weights.
According to the paper on Sensitivity and Psychological Methods (2004, p. 6), along the line of absolute threshold, scientific research indicated that individuals are very sensitive and respond to the application of a stimuli. However, a jnd can occur for people and depends on the standard stimuli.
Research has shown that “people’s sensitivity to change depends on the reference level (Standard stimulus) against which the change is compared. The stronger or more intense the reference stimulus is, the larger will be the jnd” Sensitivity and Psychological Methods (2004), hence the two kinds of thresholds, sensitivity to both change in weight or pressure and the sensory event results.
This implies that the jnd depended on the applied standard stimuli’s magnitude with which the difference for comparison had to be based on. Thus, Weber concluded that there was a quantitative relationship between jnd and the standard stimuli expressed in Weber’s law expresses as k = jnd / Standard, where k, Weber’s fraction relies on sensitivity dimension under evaluation which gives the quantitative value of sensitivity.
This brought to light the mathematical relationship between stimuli and perception as a logarithmic relationship. There was a noticeable change in weight perceived to have a relationship with the initial value of the applied weight. In addition, the mathematical relationship showed that perception varied arithmetically while the applied stimulus varied geometrically, thus valid for the weight sensation.
On the other hand, Fechner’s research on sensitivity had a basis on the three methods. This included, method of limits based on the facts that either the approach to the threshold had a basis on a value that is from below or above the threshold with the experimenter adjusting the stimuli, in this case pressure or the weights to reach the threshold value yielding different values. However, the averages of the resulting values are used.
The second method entails an adjustment with an incremental approach to stimuli variation or weight. This causes a decrease or increase in the intensity of the applied stimulus. The last method, constant stimuli, entails repeated application of stimuli of a fixed value applied randomly upon which the participant will base judgment on. The result depends on the frequency of the judgment and variation or absence of stimuli in contrast to a standard stimulus (Dinnerstein, 2000).
Methodology
In conducting the laboratory experiment on the perceptions about sensitivity to weight, 7 groups of 2-3 participants were incorporated with instructions from a laboratory instructor.
The experiment conducted in a well-lit room with chairs for the participants to sit on, and two questionnaires were administered, one to each participant and the other to the experimenters. The participants’ questionnaire consisted of 15 sets of 10 blocks numbered from 1 through to 10, with each set of 3 letters labeled horizontally, listed as L,R,S, to indicate the difference in weight perceived by each participant.
The experimenters’ questionnaire, however, consisted of one’s personal i.d. In addition, a body of experiment sheet where the weight gains in grams of each cup noted. An assigned amount of pellets distributed in the experiment cups along with the weight in grams of cup with a response section labeled 1 to 10, with an amount of weight of bb pellets in grams added in a randomized manner. Available was a digital scale for use.
Population and sampling
In conducting the research on people’s perception about sensitivity on weight, a random sample of 7 groups was chosen consisting of 2-3 participants. Random sampling technique was used where each member in the class was equally likely to participate in the experiment.
Procedure
During the experimentation, 5 pairs of cups with markings at the bottom were provided, marked S and E, and with bb weighted pellets in grams placed in order of increasing weight from 6.8g to 36.8g. Each participant was required to manipulate a weighted cup in the left and right hands. Upon noticing a difference in weight, the participant was to note it down, with the heavier one marked as L and the lighter as R while S implied no noticeable change.
Two sets of experiments were conducted, with the first half being a one-way ANOVA test to determine the difference amongst the 5 levels of standard weights and post-hot tests conducted for comparisons of each of the ten masses. The second set involved another one-way ANOVA test with 5 standard masses to determine if a change in weight proportion changed or remained constant or if it was a function of the standard weight. In addition, and post-hoc tests conducted to make 10 comparisons by comparing each standard to another.
Results and Discussion
While conducting the experiment, results showed that a change in weight of the standard cup relied upon a change in weight of the experimental cup. Thus, a significant change in weight of the experimental cup caused a perception about a change in weight of the standard cup.
This followed the ANOVA test performed with a marked significant effect. The first set of tests verified the hypothesis: weights in the experimental cup were required to cause a perceived change in weight, as the weights in the standard cup were incremented.
In conducting the experiment, a one-way anova test performed to compare the raw change in weight needed to cause a perceived change in weight thus a detectable difference across the five cups was registered. According to the findings from the experiment, as is illustrated in the table below on a one-way ANOVA test, there was a marked difference between the difference in the sum of the squares between different groups and within similar groups, with a mean square difference of (132.813-7.354) 125.459.
One-way ANOVA
DV=change in weight
According to the data obtained from the experiment, it was determined that ANOVA had a significant effect, which impelled the researcher to carry out further experiments. Further post-hoc, Turkey, experiments were conducted to determine and explain the nature of the differences that were noted with the ANOVA tests. There were reported significant differences when comparisons performed on the results. On a 95% confidence interval, there was a mean difference at a significance level of 0.05.
The second analysis involved an evaluation of a change in weight proportion. From the experimental results, it showed that a change in weight proportion was a function of the standard weight. In conducting the experiment, a one-way ANOVA test involving 5 standard masses showed results of significant differences among the weighted mean. This Verifies the second hypothesis: change in weight proportion remained a constant function of the standard weights. As the results, illustrate in the table below.
The above graph clearly illustrates the change in intensity against weights that allow a difference in perception..
(A) Limitations
However, the experiment was not without limitations. The population size was small, negatively affecting the validity of the results despite the high significance noted. In addition, the demographic distribution of the sample had a degree of biasness, as students were the only participants in the experiment. Budgetary allocations and time were also limited. This in essence led the researcher to conduct the experiment within a limited population.
Conclusion and Recommendations
Results from the one-way ANOVA tests done by comparing 5 standard weights to an experimental cup with weights added gradually. The post-hoc tests performed to compare each of the weights indicated that there was a perceived change in weight proportion, thus a perception that change in weight in the experimental cup influenced the perception about a change in weight in the standard masses. In addition, the second set of experiment verified the hypothesis that a change in weight proportion remained a function of the standard weight.
Therefore, a mathematical relationship existed between the weights and an individual’s sensitivity. In addition, the researcher recommended that more participants, time allocation, and the population sample distribution be important factors in any future research. Further still, two sets of people may be tested. One group made aware of the purpose of the experiment while the other group psychologically prepared. The results compared to open up further areas of research on the topic.
References
Dinnerstein, D. (2000), Intermanual Effects of Anchors on Zones of Maximal Sensitivity in Weight- Discrimination, The American Journal of Psychology, Vol. 78, No. 1 (Mar., 1965), pp. 66-74 American Journal Psychology, Retrieved from https://www.jstor.org/stable/1421082?seq=1#page_scan_tab_contents
Sensitivity and Psychological Methods (2004), Web.