What is a p-value anyway?

Question 1

What are the 3 components of statistics?

Answer 1

Statistics involves estimation, inference and study design.

Question 2

What is estimation?

Answer 2

Estimation is about trying to work out how large or small something is.

Question 3

What is inference?

Answer 3

Inference is about drawing conclusions, usually by conducting a statistical test of a hypothesis.

Question 4

What is a hypothesis?

Answer 4

A hypothesis is a statement about the world that could be tested to see whether it is true or false.

Question 5

Why do statistician have a say in how a study should be designed?

Answer 5

Many studies produce numbers: as experts in numbers, statisticians often have a lot to say about how exactly a study should be designed.

Question 6

What is a mean?

Answer 6

What most people call an ‘average’ is what statisticians call a mean. To calculate a mean, think of your data as a list of numbers, add up all the numbers and then divide by the number of items on your list.

Question 7

What is a median?

Answer 7

Themedianis the numberthat is halfway into the set. Tofindthemedian, the data should be arranged in order from least to greatest. If there is aneven numberof items in the data set, then themedianis found by taking the mean (average) of the two middlemostnumbers.

Question 8

What is an outlier?

Answer 8

An outlier is when you have an observation that doesn’t follow the pattern of the data.

Question 9

When you have outliers, which gives a fairer reflection of the data, the mean or the median?

Answer 9

When you have outliers, the median often gives a fairer reflection of the data than the mean.

Question 10

Which are better for planning and making decisions, the mean or median?

Answer 10

Generally speaking, means are better than medians for planning and making decisions.

Question 11

What is the a measure of spread?

Answer 11

The measure of spread helps you to know how much the data vary around the average.

Question 12

What is standard deviation?

Answer 12

The measure of spread normally reported with a mean is the standard deviation.

Question 13

What is the interquartile range?

Answer 13

The measure of spread normally reported with a median is the interquartile range

Question 14

What Is skewness?

Answer 14

Skewness, in statistics, is the degree of distortion (DoD) from the symmetrical bell curve, or normal distribution, in a set of data.

Question 15

What are descriptive statistics?

Answer 15

Statistics used to describe a data set, means and medians, standard deviations and interquartile ranges, are known as descriptive statistics.

Question 16

What is negative skew?

Answer 16

The long “tail” is on the negative side of the peak. People sometimes say it is “skewed to the left” (the long tail is on the left hand side). The mean is also on the left of the peak.

Question 17

What is a normal distribution?

Answer 17

A Normal Distribution has No Skew. It is perfectly symmetrical. The Mean is exactly at the peak.

Question 18

What is positive skew?

Answer 18

Positive skew is when the long tail is on the positive side of the peak, and some people say it is “skewed to the right”. The mean is on the right of the peak value.

Question 19

What are measures of frequency?

Answer 19

Count, Percent, Frequency. They shows how often something occurs. Use this when you want to show how often a response is given.

Question 20

What are measures of central tendency?

Answer 20

Mean, Median, and Mode. Locates the distribution by various points. Use this when you want to show how an average or most commonly indicated response.

Question 21

What is a variable?

Answer 21

A variable is a quantity whose value changes.

Question 22

What is a discrete variable?

Answer 22

A discrete variable is a variable whose value is obtained by counting. Examples: number of students present, number of red marbles in a jar, number of heads when flipping three coins, students’ grade level

Question 23

What is a continuous varable?

Answer 23

A continuous variable is a variable whose value is obtained by measuring. Examples: height of students in class, weight of students in class, time it takes to get to school, distance traveled between classes.

Question 24

What is Mode?

Answer 24

The mode is the number that appears most frequently in a set. A set of numbers may have one mode, more than one mode, or no mode at all.

Question 25

What is bias?

Answer 25

Bias describes a problem with the design, conduct or analysis of a study.

Question 26

What is a Normal Distribution?

Answer 26

A bell-shaped density curve described by its mean and standard deviation . The density curve is symmetrical, centered about its mean, with its spread determined by its standard deviation.