When a correlation value is reported in research journals, there often is not an accompanying scatterplot. Explain why reported correlation values sho

facas9 2021-06-08 Answered
When a correlation value is reported in research journals, there often is not an accompanying scatterplot. Explain why reported correlation values should be supported with either a scatterplot or a description of the scatterplot.

Expert Community at Your Service

  • Live experts 24/7
  • Questions are typically answered in as fast as 30 minutes
  • Personalized clear answers
Learn more

Solve your problem for the price of one coffee

  • Available 24/7
  • Math expert for every subject
  • Pay only if we can solve it
Ask Question

Expert Answer

Asma Vang
Answered 2021-06-09 Author has 24321 answers
The correlation coefficient of two variables may be large even though these two variables aren’t even related. First we'd have to prove that these variables are related (using scatterplot, for instance), and then using the correlation coeflicient find "how much” they are related.
Another issue is that outlieracan significantly change the correlation coefficient (one can easily construct an example where only 1 outlier can change not, only the magnitude of the correlation coefiicient, but also its sign!). Therefore, the value of correlation coefficient is a very useful tool, but only if we are aslo provided with the scatterplot
Not exactly what you’re looking for?
Ask My Question
10
 

Expert Community at Your Service

  • Live experts 24/7
  • Questions are typically answered in as fast as 30 minutes
  • Personalized clear answers
Learn more

Relevant Questions

asked 2021-06-25
Use a scatterplot and the linear correlation coefficient r to determine whether there is a correlation between the two variables. x y 1 3 0 1 15 5 2 6 3 8
asked 2021-05-31

The accompanying data on y = normalized energy \(\displaystyle{\left(\frac{{J}}{{m}}{2}\frac{{J}}{{m}^{{2}}}\right)}\) and x = intraocular pressure (mmHg) appeared in a scatterplot in the article “Evaluating the Risk of Eye Injuries: Intraocular Pressure During High Speed Projectile Impacts” (Current Eye Research, 2012: 43–49); an estimated regression function was superimposed on the plot.
x2761197642571339801278219008 y155314999328131667874116526 x2078219028143979606390525731 y267701652698686640122030730
The standardized residuals resulting from fitting the simple linear regression model (in the same order as the observations) are .98, -1.57, 1.47, .50, -.76, -.84, 1.47, -.85, -1.03, -.20, .40, and .81. Construct a plot of e* versus x and comment. [Note: The model fit in the cited article was not linear.]

asked 2020-10-26

Sketch a scatterplot where the association is nonlinear, but the correlation is close to \([r = -1]\).

asked 2021-05-29
Sketch a scatterplot with two groups of cases (business and academic) that illustrates how a strong positive correlation within each group and a negative overall correlation can occur together.
asked 2021-03-05

Match the values of r with the accompanying scatterplots 0.723,-0.353,0.353,0.998 and -0.998
scatterplots 1,2,3,4,5
image

asked 2021-07-05

When two targets are presented close together in a rapid visual stream, the second target is often missed. Psychologists call this phenomenon the attentional blink (AB). A study published in Advances in Cognitive Psychology (July 2013) investigated whether simultaneous or preceding sounds could reduce AB. Twenty subjects were presented a rapid visual stream of symbols and letters on a computer screen and asked to identify the first and second letters (the targets). After several trials, the subject's AB magnitude was measured as the difference between the percentages of first target and second target letters correctly identified. Each subject performed the task under each of three conditions. In the Simultaneous condition, a sound (tone) was presented simultaneously with the second target; in the Alert condition, a sound was presented prior to the coming of the second target; and in the No-Tone condition, no sound was presented with the second target. Scatterplots of AB magnitude for each possible pair of conditions are shown below as well as the least squares line for each.

a. Which pair of conditions produces the least squares line with the steepest estimated slope?

b. Which pair of conditions produces the least squares line with the largest SSE?

c. Which pair of conditions produces the least squares line with the smallest estimate of \(\sigma\)?

asked 2021-05-04
For each topic, decide how a scatterplot of the data would likely look. Explain your reasoning. the price of an apple at a grocery store and the price of a peach at a farmers' market
...