Independent variable

Posted by Winnie Melda on March 8th, 2019

a)      Independent variable: refers to a variable which is constantly changed or controlled in statistical analysis experiment for the purpose of testing dependent variable.

b)      Dependent variable: refers to variables being tested or measured in statistical analysis

Frequencies and frequency distribution:

Frequencies refers to count number of occurrences of values in specified group or intervals of a defined group

c)      Frequency distribution: can be defined as a table that displays frequency of identified outcomes in a sample of data the table contains summaries of distributed values 

d)     Nominal-level variable: Nominal level variable I also called categorical variable. It is a variable having two or more categories without having a natural order. The variables are characterized by absence of numeric values for example occupation

e)      Ordinal-level variable: refers to variables where their intervals between values cannot be interpreted or arranged in specific order. In ordinal level variables, the distance between variables does not have a meaning.  

f)       Interval-level variable: refers to a measurement where differences between values are meaningful. For instance, an example that shows the difference between temperatures of 70 0C and 60 0C is same or equal to difference of temperatures between 60 0C and 50 0C 

g)      Ratio-level variable: refers to interval variables that have added conditions such that the value 0 (zero) means there are no variables. Hence variables such as temperature are not a ratio variable since temperatures at 0 0C do not mean that there is no temperature.

h)      Percentage: refers defining values per hundred. It is calculated by dividing totals or whole numbers by 100. Expressed as %

i)        Proportion: refers to a fraction of the total that consisting a specified attribute. For example in a sample consisting of cow, goat, chicken, and man can be used to define the proportion of animals having four legs is 2/4 or 0.50.

j)        Rate: refers to the occurrence of various events within a specific interval of time. Rate may also refer to measure the frequency of values of interest.

k)      Ratio refers to results obtained when another quantity divides a number or quantity. It is a mathematical tool used for simplifying importance relationships that are not clear in the mass of data. It facilitates easy comparisons.

l)        Bar chart: it is also known as a bar graph. It is a chart or graph representing grouped data with rectangular bars, and their lengths define proportional values that they present. Bars can be presented either vertically or horizontally. It, therefore, represents vertical or horizontal bars to reveal comparison among different categories.

m)    Histogram; refers to a vertical or horizontal representation of statistical data and information using rectangles that reveal the frequency of data items in successful numerical intervals of equal sizes. The standard histogram represents independent variables plotted on the horizontal axis while the dependent variable is plotted on the vertical axis.

n)      Line graph: are also known as a line chart or line graph. It refers to a type of chart for displaying information in linear or series form consisting of data points or markers connected using a straight line. 

Polygon: A Frequency polygon refers to graphical devices for understanding shapes of distributions. They are most important for comparing sets of data and information. They display cumulative frequency distributions. And serve in place of histograms.

o)      Pie chart: It is also called circle chart defines statistical data by dividing it into numerical proportions. The arc and angle at the center angle show actual quantity.

p)      Time plot: it is also known as time series graph. Its purpose is defining values against time. Time plot graphs are characterized by displaying time variables specifically on X-axis

q)      Cumulative frequency distribution: refers to the sum of a total number of observations that lie above or below sets of rates in the data set. It is calculated from frequency distributed data.

r)       Cumulative percentages: refers to an alternative way of expressing frequency distribution. It is calculated by defining the percentage of cumulative frequency in each interval.

s)       Interval Width: refers to a value used in dividing the usage distribution into usage rate of intervals

t)       Normal distribution: refers to the area under normal curve equal to 1.0. The normal distribution is taken to be denser at the middle and less dense at the ends. The normal distribution is shown by mean and standard deviation, and its area is within one standard deviation of the calculated mean.

u)      Outlier: refers to a specific observation made that is distant from other relative distance. The outlier is used to indicate variations in measurements due to errors encountered from the data set.

v)      Skewed distribution: refers to a measure of the asymmetry of the probability distribution of real values chosen at random variables about its mean. Skewed distribution can either be positive, negative or undefined.   

References

Ronet B., & Raymond P., (2007). Statistical Methods for Criminology and Criminal Justice (3rd edition) McGraw-Hill Companies; USA

Carolyn Morgan is the author of this paper. A senior editor at MeldaResearch.Com in research paper writing services if you need a similar paper you can place your order from Top American Writing Services.

Like it? Share it!


Winnie Melda

About the Author

Winnie Melda
Joined: December 7th, 2017
Articles Posted: 364

More by this author