Difference between ANCOVA and ANOVA
ANCOVA vs ANOVA:
ANCOVA and ANOVA are different technical systems which are used for statistical analysis and it may be very difficult to tell the different between these two because of the apparent similarities of the purpose and the methods. Thereby, this article serves as a means by which we seek to emphasize the differences between these two statistical models at the same time providing brief introductions for both.
What is ANCOVA?
Analysis of covariance, better known and ANCOVA, is a generally linear model with a with a continuous outcome variable which consists of one or more continuous predictor or one nominal and non-scaled( catogorical) predictor variable. It possesses a covariate and its provides an interpretation that depends upon certain assumptions made about the data that has been fed in to the model.
What is ANOVA?
Analysis of Variance, also known as ANOVA, examines and compares three or more variables in a population which is thus based on a sample that has been presented. It is a statistical tool which is used in various fields such as agriculture, psychology, and different industries and its key statistics can be listed as the key statistic is the F-test of the difference of group means. There are different types of ANNOVA models such as Fixed-effects models, random-effects models and mixed-effects models.
What is the difference between ANOVA and ANCOVA?
ANOVA and ANCOVA are very much alike and therefore, telling the difference between the two can be quite a task. Yet, one such deference between the two is the fact that while ANCOVA makes use of a covariate, ANOVA does not depend on it. Also, ANOVA consists of many statistical models in which ANCOVA is a model.
The following formula is used to calculate the ANOVA model – BG variation attributed to IV divided by WG variation attributed to individual differences, while ANCOVA model is calculated using the formula- BG variation attributed to I+ BG variation attributed to COV divided by WG variation attributed + WG variation attributed to individual differences to COV. ANOVA also exclusively features BG variation to treatment while ANCOVA separates BG variation into COV and TX. Another factor that sets the two apart is that while ANCOVA separates the WG variation into COV and individual differences, ANOVA features the WG variation only to individual differences.
Although both the techniques seem to be quite similar, it is considered that ANNOVA possesses more power than ANCOVA.