Ch. 1 Inferential Statistics

What 2 types of Classifications does Quantitative Variables have?

Discrete and Continuous Variables

Descriptive Statistics

Methods of organizing, summarizing and presenting data in an informative way (simple data not analyzed, uses lots of numbers)

Interval Level

Similar to the ordinal level, with the additional property that meaningful amounts of differences between data values can be determined. There is no natural zero point ( temp. On the Fahrenheit scale) quantitative variable"

Single blind experiment

Subjects do not know if they are in a control or treatment group but the testers do

What are variables contributing to confounding variables?

Treatment, subjects, gender, height, allergies, placebo affect

What are the properties of the Interval Level?

1. Data classifications are ordered according to the amount of the characteristic they possess 2. Equal differences in the characteristic are represented by equal differences in the measurements Ex: woman's dress sizes listed on a table graph

Population

A collection of ALL possible individuals, objects or measurements of interest

What are the 4 types of studies?

1. Cross sectional 2. Longitudinal 3. Meta- Analysis 4. Case Study

Placebo effect

A response to the power of suggestion rather than the treatment itself by participation of an experiment

Inferential Statistics

A decision, estimate, prediction or generalization about a population based on a sample (inquiring more info)

Control group

A group of subjects to which no treatment is applied in an experiment

Treatment group

A group of subjects to which researchers apply a treatment in an experiment

Sample

A portion or part of the population of interest

Meta-analysis

A study that complies information from previous studies

Case study

A study that looks at multiple variable that affect a single event

Cross- sectional study

A study where data is collected at a single point in time Ex: polls and surveys

Longitudinal study

A study where data is gathered by following a particular group over a period of time Ex: national longitudinal study of adolescence health over 14 years

Placebo

A substance that appears identical to the actual treatment but contains no beneficial elements

Continuous Variables

Can assume any value within a specific range (any number) ex: the pressure in a tire

Discrete Variables

Can only assume certain values and there are "usually" gaps between values ( must be whole numbers)

Bias

Choosing a particular portion directly or indirectly

Confounding variables?

Factors that can alter an experiment

Quantitative Variable

Information is reported (Numerically) ex: amounts, number of children in a family, minutes remaining in a class (interval level)

Statistics

Is the science of collecting, organizing, presenting, analyzing, and interpreting numerical data to assist in making more effective decisions

Qualitative or attribute Variables

The characteristic being studied is (Non-numeric) ex: gender, eye color, state of birth etc. (nominal level)

Ratio Level

The interval level with an inherent zero starting point. Differences and ratios are meaningful for this level of measurement ( monthly income of surgeons)

Why is it important to know the levels of measurement?

1. Because it dictates the calculations that can be done to summarize and present the data 2. To determine the statistical tests that should be performed on the data

What are the properties of the Ratio Level?

1. Data classifications are ordered according to the amount of the characteristics they possess 2. Equal differences in the characteristic are represented by equal differences in the numbers assigned to the classifications 3. The zero point is the absence of the characteristic and the ratio between two numbers is meaningful

What are the properties of the Ordinal Level?

1. Data classifications are represented by sets of labels or names ( high, medium, low) that have relative values 2. The data classified can be ranked or ordered due to the relative values

What are the properties of Nominal Level?

1. Observations of the qualitative variable can only be classified and counted 2. There is no particular order to the labels

What are the components of the Scientific Method?

1. State the problem 2. Formulate a hypothesis 3. Perform experiment 4. Collect data ( using 1 of the 4 levels measurement 5. Make a conclusion (statistics)

What are the 4 types of Experimental Groups?

Control Treatment Single blind Double blind

Ordinal Level

Data arranged in some order but the differences between data values can not be determined or are meaningless ( abc order)

Nominal Level

Data that is classified in categories and can not be arranged in any particular order ( eye color, gender, religion, name) "qualitative variable"

What are the 2 types of statistics?

Descriptive and Inferential

Double blind experiment

Neither subject nor testers know to which group each subject belongs

What are the 4 levels of measurement?

Nominal, Interval, Ordinal and Ratio level

What are 2 types of Variables

Qualitative and Quantitative

Practically all quantitative data is recorded on what level of measurement?

Ratio Level

What is the "highest" level of measurement?

Ratio Level