| Natalie Raso - Weapons of Targeted Destruction: Using Viruses to Kill Cancer | Statistical Analyses |
| Project
Information Abstract Project Summary Background Purpose Scientific Thought Hypotheses Apparatus and Materials Genetically Engineered KM110red Herpesvirus Methodology Procedure for Cell-Line Splitting Procedure for KM110r Infection Procedure for Immunofluorescent Microscopy Imaging Statistical Analyses Proliferation Assay Analyzed Data Major Results Graphed Results Discussion of Statistics Controls and Variables Conclusions Discussion Discussion of KM110r Efficacy Successes and Failures Sources of Error and Data Limitations Future Research Applications Glossary Bibliography Acknowledgements |
Statistics are a way of assessing
the quality of information being evaluated. The types of statistical
analysis primarily relied upon in this study are mathematical mean
(average), standard error t-probability, and Analysis of Variation between
groups (ANOVA). The null hypothesis states that all
means are equal and there is no difference between them. Therefore the alternative
hypothesis tested is that the means are unequal. The following statistical analyses
were carried out to determine if the null hypothesis should be rejected or
accepted. Mathematical mean, or mean, is the
same as average. It is calculated by determining the sum of all samples,
and dividing by the n variable.
Mathematical mean, or average, is a valuable descriptive statistic used in
the analysis of the data collection. The standard error of a sample of sample size n is the sample's
standard deviation divided by the
squareroot of n T-probability
can be referred to as p value or t-test. The t-Test is used to compare the means of two
samples. Specifically, this can be used to determine whether or not the
means in two samples are significantly different. If the outcome (p value)
is less than However when a t-test is used on its
own to test significance, the chance of encountering a Type I error
increases. A Type I error is a false positive which shows significance
where there isn’t. To avoid a possible Type I error, and since the t-test
only measures differences between two groups, a more powerful approach is
to analyze all the data together. The model is similar and is called a
one-way ANOVA and the test statistic is the F ratio. T-tests are a special
type of ANOVA: if the means of only two groups are being analyzed by
ANOVA, the same results are achieved as would have been achieved
conducting the analysis with a t-test[2].
ANOVA tests whether there is
statistical significance among the means of more than 2 groups, i.e. it
tests the variability among group means. ANOVA uses various statistics (sum
of squares, degrees of freedom and mean squares) to produce the F-ratio
and the sig. value. The F-ratio is a measure of how different the means
are relative to the variability between each sample. The larger this
value, the greater the chance that the differences between the means are
due to something other than chance alone, namely real effects. For the
F-ratio to be considered statistically significant, it has to be
significantly greater than 1. Like the t-test, if the significance (sig.)
value is less than an alpha level of 5% the result is statistically
significant and the null hypothesis can be rejected. So an ANOVA test
determines whether there is a difference among the means of the groups.
[1] Kenney, J. F. and Keeping, E. S. "Standard
Error of the Mean." § [2] Rutherford A,
Introducing Anova and Ancova :
A GLM Approach. Sage Publications, 2001.
|