Pearson Correlation Assumptions

The assumptions of the Pearson product moment correlation can be easily overlooked. The assumptions are as follows: level of measurement, related pairs, absence of outliers, normality of variables, linearity, and homoskedasticity.

Level of measurement refers to each variable. For a Pearson correlation, each variable should be continuous.  If one or both of the variables are ordinal in measurement, then a Spearman correlation could be conducted instead.

Related pairs refers to the pairs of variables. Each participant or observation should have a pair of values. So if the correlation was between weight and height, then each observation used should have both a weight and a height value.

Absence of outliers refers to not having outliers in either variable. Having an outlier can skew the results of the correlation by pulling the line of best fit formed by the correlation too far in one direction or another.  Typically, an outlier is defined as a value that is 3.29 standard deviations from the mean, or a standardized value of less than ±3.29.

Linearity and homoskedasticity refer to the shape of the values formed by the scatterplot. For linearity, a “straight line” relationship between the variable should be formed.  If a line were to be drawn between all the dots going from left to right, the line should be straight and not curved.  Homoskedasticity refers to the distance between the points to that straight line. The shape of the scatterplot should be tube-like in shape. If the shape is cone-like, then homoskedasticity would not be met.

Dissertation Data Analysis

You’ve spent months gathering the data that you need for your dissertation, you’ve been working on your dissertation for what seems like forever, you finally are at the point where you can start making conclusions that will apply to your thesis… and then you realize, “I’m not exactly sure how to make sense of all of this data! I’m not exactly sure how to do the dissertation data analysis!”

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While it takes months and months and months to gather accurate and valid data, that time spent on gathering the data can be wasted if the data is not then used properly—if proper dissertation data analysis is not performed correctly. Dissertation data analysis is very difficult to perform, especially if the doctoral student is working on his or her first dissertation. Dissertation data analysis is especially difficult to perform because it requires that the doctoral student knows all there is to know about statistics, statistical procedures and statistical methodologies. Thus, without the proper expertise and know-how in statistics, doctoral students can flounder through the dissertation data analysis part of the dissertation, and essentially, all the hard work and energy spent on gathering accurate data can be wasted.

This does not have to happen, however, as there are dissertation consultants who can help any doctoral student with the dissertation data analysis. Indeed, dissertation consultants can help the student make sense of the dissertation data analysis and dissertation consultants can provide the knowhow and expertise that the PhD student lacks. This is especially helpful in the dissertation data analysis phase, as a dissertation consultant is trained in all things concerning statistics—including having extensive training in dissertation data analysis.

There is no sense, then, for a PhD student do “go it alone” and attempt to figure out the dissertation data analysis parts of the dissertation all by him/herself. Help on the dissertation data analysis is incredibly easily attainable because dissertation consultants are very easy to contact and to obtain. In fact, a simple internet search will yield thousands of hits for dissertation consultants—mainly because dissertation consultants are that good at helping students on their dissertations and on the dissertation data analysis portions of their dissertations. For help on the dissertation data analysis, there is no better solution than to seek the professional help of a dissertation consultant who can take any PhD student through the lengthy, difficult and challenging aspects of the dissertation data analysis.

Many students hesitate, however, before seeking help on the dissertation data analysis and before contacting a dissertation consultant. PhD students hesitate for several reasons, one of them being the fact that they are so used to doing everything alone. It is always good to get help, however, and this is equally true on the dissertation data analysis. Some students, while ready to get help, wonder if it is ethical to use a dissertation consultant to get help on the dissertation data analysis. While this is definitely worth thinking about, it is absolutely imperative that a PhD student understand that a dissertation consultant simply helps a student—simply offers assistance in the challenging aspects of the dissertation. A dissertation consultant, then, does NOT do the work for the student. Rather, a dissertation consultant instructs the student and provides the student with very valuable teachings. This instruction is perhaps one of the biggest benefits of getting a dissertation consultant—they do not do the work for the PhD student, they instruct the student and guide the student so that the student can do all of the statistical procedures and the dissertation data analysis on his or her own. And truly, there is no better help than this.

Dissertation Data Analysis

The dissertation is the single most important part of any doctoral student’s career because the dissertation is the last step that a doctoral student must take if he or she is to receive his or her doctoral degree and graduate with the title of “Dr.” The dissertation, then, needs to be completed carefully and meticulously as it will be scrutinized by professors before a student can obtain his or her degree. One of the most difficult aspects of the lengthy and time consuming dissertation is the dissertation data analysis. The dissertation itself revolves around data because the doctoral student must actually prove something new and of interest in the field in which he or she is working. The dissertation data analysis will be that proof and the dissertation data analysis will center the entire dissertation.

Statistics Solutions is the country's leader in dissertation data analysis and dissertation statistics. Contact Statistics Solutions today for a free 30-minute consultation.

Doctoral students often struggle with the dissertation data analysis because the dissertation data analysis revolves around statistics. In other words, in order to have accurate dissertation data analysis, a doctoral student must be proficient in statistics if he or she is to have valid dissertation data analysis. Dissertation data analysis also takes a lot of time, which is another reason why doctoral students often have a hard time with it. If mistakes are done in the dissertation data analysis phase, then those mistakes from the dissertation data analysis will severely affect the student’s dissertation, conclusion and results. Thus, it is very important that the dissertation data analysis is done in a precise and accurate manner.

Because dissertation data analysis can be so complicated and difficult for doctoral students, there is help available. The first source for help on the dissertation data analysis, of course, is the student’s advisor. The doctoral student’s advisor is not always available to answer questions and provide help on the dissertation data analysis, however, and for that reason, dissertation consultants are the perfect solution to getting help and working on the dissertation data analysis. Dissertation consultants can make sure that the dissertation data analysis is accurate and done correctly because dissertation consultants specialize in dissertation data analysis. The reason why dissertation consultants are a sound solution to acquiring dissertation data analysis help is because dissertation consultants are trained statisticians who specialize in both statistics and in dissertations. Dissertation consultants can look at all of the data that the student has gathered over the course of working on his or her dissertation and dissertation consultants can make sense of that data. Thus, dissertation consultants can be an immense help to students on the dissertation data analysis.

Not only can dissertation consultants help with the dissertation data analysis, however, dissertation consultants can also make sure that the data that has been collected by the doctoral student is valid, accurate and statistically sound. In order to produce accurate dissertation data analysis, one must have valid dissertation statistics and dissertation data. If that data is not valid or accurate, that will of course throw off the dissertation data analysis. Dissertation consultants know this and dissertation consultants will make sure that the data that has been collected has been collected properly, that all of the proper tests were used while collecting the data, that the correct sample sizes were used while collecting the data and that the data is not biased. Once the dissertation consultant has double checked to make sure that the dissertation data is indeed accurate, the dissertation consultants can get to work with the student on the dissertation data analysis. With the help of a dissertation consultant, then, the student will be sure to obtain his or her doctoral degree as every single part of the dissertation data and the dissertation data analysis will be correct, accurate, valid and dependable.