Flashcards in INRS Learning Unit 6 Quantitative and Qualitative Data Analysis Theme 1 Quantitative Data Analysis Deck (10):
Explain the need for statistics in quantitative data analysis 4 marks .
*Keeps objectivity = Must be non bias , clear reasons to prove that new suggested way of doing things is better that nthe current one .
*Defensible = means that there is a significant statistical benefit/significance shown in the results . Statistical significance goes above the expected margin or error. .
Explain the importance of accuracy and precision in data sets 3 marks .
*Accuracy = free from error .
*Precision = a consistency to results that doesn't refer to what the results they show are .
*These factors combine to create confidence .
Explain what is meant by the range of a data set 1 mark
*The maximum and minimum values of a data set
Explain how to determine the range of a data set . 1 mark
*Subtract the lowest value from the highest
Determine the mean , median and mode of a data set . 6 marks
*Mean : Numerical average of the data . Calculated by (total number of all values added together/total number of values)
*Median : The middle value of the values provided . The values must then be placed in numerical order . If there is an even number of samples then its the average of the middle two .
*Mode : The most common value in the data set . Determined by reordering values in numerical order .
Explain the distribution of data of a set . 2 marks
*How many times does each particular value occur in the data set ? Each value must then be counted to determine this .
Calculate the standard deviation of a data set
*The average difference of each value in the set from the mean . (Formula won't be tested)
Explain the probability density function and normal distribution .
*The bell curve of normal distribution plots probability against values . The probabilty density is therefore the chance of a particular value occuring as shown by the given graph .
Calculate a correlation co-efficient 8 marks
*Always a value from -1,0 to +1.0 .
*-1.o to -0.8 = strong negative correlation , X and Y are strongly related (Y decreases as X increases)
*-0.7 to -0.3 = weak negative correlation , X and Y may be related . Y decreases as X increases . Negative slope on the graph .
*-0.2 to +0.3 = No correlation or relationship between X and Y
*0.4 to 0.7 = Weak positive correlation , X and Y may be related . Y increases as X increases , positive slope on the graph .
*0.8 to 1.0 = Strong positive correlation . X and Y strongly related . X increases as Y does positive slope .