Stats. Chapter 1, Intro to Statistics

Name the 3 different RESEARCH METHODS (described in Chapter 1 of your book)

1) The Experimental Method 2) The Quasi-Experimental Method 3) The Correlational Method

What is a POPULATION PARAMETER?

A (usually numeric) CHARACTERISTIC that DESCRIBES a POPULATION

What is a SAMPLE STATISTIC?

A (usually numeric) CHARACTERISTIC that DESCRIBES a SAMPLE (that may or may not be inferred to the population)

What is a statistical SAMPLE?

A PORTION of ALL MEMBERS of a group (set of individuals, items, or data) of interest, usually studied because studying an entire population is often difficult and impractical.

What is a statistical POPULATION?

ALL MEMBERS of a group (set of individuals, items, or data) of interest

What is an OPERATIONAL DEFINITION and why is it used? (Part of EXPERIMENTAL RESEARCH METHOD)

Because DEPENDENT VARIABLES can often be MEASURED IN DIFFERENT WAYS, EXPERIMENTS require an operational definition: a DESCRIPTION of some OBSERVABLE EVENT in terms of the SPECIFIC MANNER BY WHICH it was OBSERVED/MEASURED *how the DV was specifically measured/defined*

What is DATA? What is its singular form?

DATA (PLURAL) are measurements/observations that are typically numeric. DATUM is the singular form but is usually referred to as the SCORE or RAW SCORE.

What are the main differences between DESCRIPTIVE and INFERENTIAL statistics?

DESCRIPTIVE statistics: Mathematics used to ORGANIZE and SUMMARIZE a group of observations (data). INFERENTIAL statistics: Mathematics used to ANALYZE, INTERPRET (INFER) a group of observations (data) and/or to infer unknown parameters in a given population (population parameters) based on data collected from a sample (sample statistics)

DISCRETE vs CONTINUOUS data and examples of each

DISCRETE data is measured only in WHOLE UNITS or CATEGORIES (e.g. number of brothers or sisters, S.E.S. class, like lower class, middle class, or upper class) CONTINUOUS data is measured along a CONTINUUM and can thus be measured in FRACTIONAL UNITS and ANY POINT BEYOND A DECIMAL (e.g. height, weight, age, etc.)

What is an INTERVAL scale and what can it tell you? What are some examples?

Interval scales are measurements that HAVE NO TRUE ZERO (when the value "0" actually indicates NOTHING on a scale of measurement) but ARE DISTRIBUTED INTO EQUAL UNITS. Because there is no true zero, RATIOS (like men were 3x as satisfied as women working this job) CANNOT BE STATED. E.g. rating scales (like 7 means completely satisfied and 1 means completely unsatisfied), Fahrenheit (0 degrees is an arbitrary temperature - does not mean there is no temperature!)

What is a NOMINAL scale and what can it tell you? What are some examples? What is CODING?

Nominal scales are measurements in which a NUMBER is ASSIGNED to REPRESENT SOMETHING or SOMEONE in a process called CODING. It conveys IDENTITY ONLY. E.g. zip codes, license plate numbers, S.S. numbers, etc.)

What is an ORDINAL scale and what can it tell you? What are some examples?

Ordinal scales are measurements that CONVEY RANK and ORDER alone. They do not show the degree of difference between two scores, just that one is higher/more than another. E.g. ranking of favorite foods, letter grades (in cases where difference between each letter grade is not provided)

QUALITATIVE vs QUANTITATIVE data and examples of each

QUALITATIVE data VARIES by CLASS and is often represented as a label and describes non-numeric aspects of phenomena (e.g. labels of behavior, like "aggressive," "passive," "assertive" etc.) QUANTITATIVE data VARIES by AMOUNT, is measured numerically and is often collected by measuring or counting (e.g. food intake in calories, food intake as pieces of food)

What is a RATIO scale and what can it tell you? What are some examples? Why do researchers go out of their way to use it (e.g. making a ratio scale to measure hunger)?

Ratio scales are measurements that HAVE A TRUE ZERO and ARE DISTRIBUTED INTO EQUAL UNITS. They can therefore BE MANIPULATED BY ANY KIND OF MATHEMATICAL OPERATION (which is ideal and why researchers seek to measure things this way). E.g. a height of zero = no height, 60 lbs is twice as much as 30 lbs, etc.

What are SCALES of MEASUREMENT? Name/describe THREE PROPERTIES that CHARACTERIZE scales of measurement. Name Stevens's FOUR TYPES of MEASUREMENT SCALES.

Scales of Measurement are basically RULES for HOW VARIABLES are DEFINED/MEASURED/CHARACTERIZED. They imply the extent to which a statistic is informative. 3 Properties that Characterize Measurement Scales: 1) ORDER (does a LARGER number indicate GREATER VALUE?) 2) DIFFERENCE (does SUBTRACTING numbers represent something meaningful?) 3) RATIO (does DIVIDING numbers represent something meaningful?) Stevens's 4 Types of Measurement Scale: Nominal, Ordinal, Interval, Ratio

What is SCIENCE according to your book?

Science is the study of phenomena, such as behavior through STRICT OBSERVATION, EVALUATION, INTERPRETATION, and THEORETICAL EXPLANATION, and the SCIENTIFIC METHOD.

Why are statistics important? Why is it important to be a critical consumer of statistics?

Statistics help us make sense of data through summary, interpretation, organization, etc. that can help us make us make important decisions. They can be used to understand our world more objectively, or they can be used to lie more effectively through selective representation, misinterpretation, skewing data, etc.

Describe the CORRELATIONAL METHOD

The Correlational Method measures the RELATIONSHIP between PAIRS of SCORES or VARIABLES but LACKS PROPER CONTROLS to SHOW CAUSALITY E.g. the relationship between the amount of time spent exercising per week and the amount of time spent on the computer per week

Describe the QUASI-EXPERIMENTAL METHOD and HOW IT DIFFERS from the EXPERIMENTAL METHOD.

The Quasi-Experimental Method is JUST LIKE the Experimental Method, EXCEPT it EITHER: Has a: QUASI-INDEPENDENT VARIABLE = a PRE-EXISTING VARIABLE that is often INHERENT to an individual or group being studied (CANNOT BE RANDOMLY ASSIGNED) (e.g. sex, the presence of a cleft palette, natural hair color when it comes to the ability to multi-task - you're not having people show up for experiment, flipping a coin on who does a certain activity - they're already sorted based on a pre-existing characteristic) Lacks a: COMPARISON/CONTROL GROUP

Describe the EXPERIMENTAL METHOD and its 3 REQUIRED CONTROL ELEMENTS

The experimental method is a series of PROCEDURES used to make OBSERVATIONS (and potentially determine CAUSALITY) in which the RESEARCHER FULLY CONTROLS the CONDITIONS and EXPERIENCES of its PARTICIPANTS through the use of the following required elements: 1) MANIPULATION - an INDEPENDENT VARIABLE (IV = presumed cause) must be manipulated to determine its effect on the DEPENDENT VARIABLE (presumed effect [MUST HAVE OPERATIONAL DEFINITION]) 2) RANDOMIZATION of assigning participants to conditions 3) COMPARISON/CONTROL - a control group (that is not the IV) that acts as a benchmark to which the IV and its effects are compared.

What is the SCIENTIFIC METHOD according to your book?

The scientific method (aka "research method" according to the book) is a SET of SYSTEMATIC TECHNIQUES used to ACQUIRE, MODIFY, INTEGRATE KNOWLEDGE concerning OBSERVABLE/MEASURABLE PHENOMENA