Introduction to Statistics Packet #18 11/17/2018 1:17:26 PM
Introduction Statistics Goals of Statistics The mathematics of the collection, organization and interpretation of numerical data. Especially the analysis of population characteristics by inference from sampling Goals of Statistics Describe what is happening now Determining the probability of what may happen in the future 11/17/2018
Vocabulary I Population Sample The entire group of interest A random group taken from the population A smaller representation of the population 11/17/2018 1:17:26 PM
Vocabulary II Properties of Scales of Measurement In order to perform a statistical procedure, one must first measure something Measurement scale, temperature for example, have different properties Magnitude The ability to know if one score is greater than, less than, or equal to another Equal Intervals Magnitude is represented by a unit of measurement that is the same no matter where it falls on the scale Absolute Zero Scale has a point that is equal to zero or a point where there is no score 11/17/2018
Vocabulary III Scales of Measurement Ratio Scale Any scale of measurement possessing magnitude, equal intervals and an absolute zero Weight Height Interval Scale Any scale of measurement possessing magnitude and equal zero but NO absolute zero Temperature* 11/17/2018
Vocabulary IV Scales of Measurement Ordinal Scale Any scale that reflects only magnitude but does not contain equal intervals or an absolute zero Ratings Class rank order 11/17/2018
True Experiment 11/17/2018
True Experiment The investigator attempts to determine if changes in one variable produce changes in another. Three requirements Must randomly divide to get two groups Manipulate some variable Measure the dependent variable Statistics is used to determine the validity of the data that is gathered. Applies for both true experiments and observational studies 11/17/2018 1:17:26 PM
Correlational Study A type of observation where the relationship between two variables is inferred Measure two variables Calculate the relationship A correlational study may be considered to be a true experiment. 11/17/2018 1:17:26 PM
Branches of Statistics 11/17/2018
Descriptive Statistics Analysis is conducted to describe the obtained data. Makes large amounts of data easy to understand Use of numerical data to describe a phenomena An observable fact or event Examples Baseball/Softball batting average Industry production Government deficits Number of children in a each family along a city block 11/17/2018 1:17:26 PM
Numerical Statistics Numbers, numbers and more numbers! Clearly, some numbers are more meaningful than others Buy vehicle #1 for $1 Buy Vehicle #2 for $1000 The mean (average) of the two prices will be an important statistic 11/17/2018 1:17:26 PM
Pictorial Statistics Taking numerical data and presenting it in pictures and/or graphs Visual displays (graphs) are the easiest presentation Why? Vision may be a human’s best ability to understand material Complex information is better memorized visually 11/17/2018 1:17:26 PM
Inferential Statistics Analysis is conducted to make inferences (derived as a conclusion from facts or premises) about a population using data obtained from the sample Uses descriptive and probability theory to make judgments about reality Previously covered Did “this” cause “that?” 11/17/2018 1:17:26 PM
Statistics and The Scientific Method 11/17/2018
The Relation Hypothesis Recording & Analyzing data Probability Allows the investigation of the independent variable on the dependent variable True Experiment Recording & Analyzing data Statistics provides an analysis of data that determines whether your data is accurate Probability One of the most familiar uses of statistics is to determine the chance of some occurrence. If…then statement (Hypothesis) Example Flipping a coin to see how many times it lands on heads or tails 11/17/2018 1:17:26 PM