Stats - Chapter 1

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Political affiliation (republican, democrat)

-discrete -qualitative -nominal

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Season

-discrete -qualitative -nominal

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Sex (male, female)

-discrete -qualitative -nominal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement A letter grade (A,B,C,D,F)

-discrete -qualitative -ordinal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement A college student's SAT score

-discrete -quantitative -interval

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Ratings of satisfaction (1 to 7)

-discrete -quantitative -interval

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Rating of satisfaction (1 to 7)

-discrete -quantitative -interval

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Position standing in line

-discrete -quantitative -ordinal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Ranking of favorite foods

-discrete -quantitative -ordinal

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement A letter grade

-discrete -quantitative -ordinal

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Ranking of favorite food

-discrete -quantitative -orinal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Number of dreams recalled

-discrete -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Number of errors

-discrete -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Number of lever presses per minute

-discrete -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Number of students in your class

-discrete -quantitative -ratio

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Number of errors

-discrete -quantitative -ratio

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Number of people in our class

-discrete -quantitative -ratio

3 common research methods

-experimental method -quasi experimental method -correlational method

Examples of variables

-gender -GPA -economic status

Nominal

-identity or classification -gender (1=female, 2=male), political affiliation (1=republican, 2=democrat), body type (1=slim, 2=average, 3=heavy)

What happens to the mean when you change an existing score?

-it will change -when you increase the value of an existing score the mean will increase -when you decrease the value of an existing score the mean will decrease

What is needed to satisfy experimental method?

-manipulation -randomization -comparison/control

What is mean reported for?

-normal distributions of data -only interval and ratio scale data

Ratio

-order, equal units, absolute zero -height in inches, weight of an infant, duration of drug abuse, scores on an exam (from 0% to 100%)

Ordinal

-rank or order and no equal units -Class rankings first through last, ranking of favorite food, letter grade (1=a,2=b,3=c,4=d,5=f)

Ratio scale

-same as interval scale but has true origin -zero means absence of what is being measures (income $0 means no income, weight, height, length)

What is median reported for?

-skewed distributions of data -ordinal scale data (not for nominal scale data)

What is modal distributions of data?

-unimodal distributions (one mode) -bimodal distribution (two modes) -multimodal distribution (more than two modes) -nonmodal distribution (no modes)

Rules for correlational method

-variables measured as they naturally occur -lack of random assignment -lacks control to determine cause-effect

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Sex (male, female)

-discrete -qualitative -nominal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Type of distraction (auditory, visual)

-discrete -qualitative -nominal

Types of statistics

descriptive and inferential

How to find the interval width

divide the real range by the intervals needed

Population

entire set of individuals or items of interest. the group that scientists will generalize

A researcher tests whether the dosage level of some drug (low, high) causes significant differences in health. To do this, the researcher randomly assigns rat subjects to receive a low or high dosage of the drug and records health-related measures in both groups. The type of method described is

experimental

2 types of groups

experimental and control

Experimental group

exposed to manipulation

Inferential stats do what?

generalize to population

Interval scales of measurement A) have equidistant scales B) have a true zero C) both a and b

have equidistant scales

Benefits of experimental method

high level of control to isolate cause and effect

What is an operational definition?

how the DV will be measured

Examples of scales of measurement

identity, order, equal distance, absolute zero (complete absence of the variable)

What does randomization (random assignment) do?

renders groups equivalent

What is nominal scale data

represents something or someone; it is not a quantity

Exhaustive categories

response categories that cover the full range of possible responses

M means

sample mean

Data for samples are called?

sample statistics

What is most behavioral stats done on?

samples

x means

score or response

Levels

specific values of an independent variable

Experimental research

studies that seek clues to cause-effect relationships by manipulating one or more factors (independent variables) while controlling others (holding them constant)

How to find the real range?

subtract the least from the most data amount and add 1

Descriptive stats do what?

summarize sample results

Examples of interval scale

temperature, time

What does random assignment mean

that experimental units are assigned to treatments at random

Qualitative variables

variables that can be placed into distinct categories, according to some characteristic or attribute

Independent variable

variables that were manipulated (presumed cause)

Identify the dependent variable and independent (or quasi-independent) variable. A researcher tests whether smoking by parents influences children's attitudes toward smoking behavior.

IV smoking DV childrens attitudes toward smoking behavior

Identify the dependent variable and independent (or quasi-independent) variable. A student tests whether tutoring from a tutor improves performance on a standardized exam.

IV tutoring DV performance on a standardized exam.

Identify the dependent variable and independent (or quasi-independent) variable. A researcher tests whether the type of distraction during recall (auditory or visual) influences the number of words participants are able to recall from a list.

IV type of distraction during recall (auditory or visual) DV the number of words participants are able to recall from a list.

Identify the dependent variable and independent (or quasi-independent) variable. A psychologist tests whether employee satisfaction is different among employees working different shifts (day or night shifts).

IV working different shifts (day or night shifts). DV employee satisfaction

Nominal scale of measurement

Lowest of the four levels of measurement Categories that are not more or less, but are different from one another in some way Mutually exclusive and exhaustive categories Named categories Example: Gender 1 = Male 2 = Female

Statistics

Mathematical procedures used to summarize, analyze and interpret observations (5 senses)

Control group

Not exposed to manipulation

Data

Numbers assigned to observations according to rules, called scores or raw scores

Interval scale of measurement

Numerical distances between intervals Absence of a zero point Like scale scores 1 = Strongly disagree 2 = Disagree 3 = Neutral 4 = Agree 5 = Strongly agree

What is the gold standard scale of measurement?

Ratio scale

Research method

a set of systematic techniques used to acquire, modify and integrate knowledge concerning observable and measurable phenomena

Treatment

a specific condition that the experimental unit receives

Correlational stats

a statistical technique that can show whether and how strongly pairs of variables are related

What is an experiment?

a study in which we actually do something (a treatment) to people, animals, or objects (experiment unit) to observe the response

What is an independent variable (IV)?

a variable that is manipulated, the proposed cause

Discrete variable

a variable whose value is obtained by counting (whole #)

What is experimental method used for?

cause-effect analysis

What are the scales of measurement?

degree to which measured variables conform to the abstract number system

Sample

a representative subset of a population

Raw scores

data that have not yet been transformed or analyzed

What scale of measurement can be used for order?

ordinal, interval, ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Body type (slim, average, heavy)

-discrete -qualitative -nominal

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Political affiliation (republican or democrat)

-discrete -qualitative -nominal

What is mode reported for?

-Modal distributions of data -nominal scale data

Interval scale

-Numerically equal distances on the scale represent equal distances on the underlying dimension -zero does not mean the absence of what is being measured

Interval

-Order and equal units, no true zero -Intelligence test scores, temperature, ratings of satisfaction (1=strongly disagree to 5=strongly agree)

Descriptive statistics

-Summarize, organize and make sense of a set of scores -procedures typically used to quantify measured behaviors -allows for clear presentation of data summary (tables, graphs, single values)

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Seasons (spring, summer, fall, winter)

-discrete -qualitative -nominal

Quasi-Experimental method includes what

-a non-manipulated IV -lack of random assignment to group and/or -lack of control group

What is correlational method used for?

-analyses for prediction -quantifies the strength and direction of a relationship between two or more variables (x and y)

Steps of research

-ask a question -set up a research study -measure behavior -evaluate findings

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Temperature (degrees fahrenheit)

-continuous -quantitative -interval

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Temperature

-continuous -quantitative -interval

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Duration of drug abuse (in years)

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Score (from 0% to 100%) on an exam

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement The size of a reward (in grams)

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Time (in seconds) to memorize a list

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Qualitative Scale of measurement Weight (in pounds) of an infant

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Duration of drug abuse

-continuous -quantitative -ratio

Continuous vs Discrete Qualitative vs Quantitative Scale of measurement Weight (in pounds) of an infant

-continuous -quantitative -ratio

Ways to classify variables

-continuous and discrete -quantitative and qualitative

Types of classification of variables

-continuous vs discrete -quantitative vs qualitative

Inferential statistics

-data typically drawn from a portion of the overall group of interest -allows researches to make inferences about parameters in a population based on a sample of data

Correlational methods

A research method that examines how variables are naturally related in the real world. The researcher makes no attempt to alter the variables or assign causation between them.

Quasi-experimental research

A research technique in which the two or more groups that are compared are selected based on predetermined characteristics, rather than random assignment and cannot manipulate the independent variable

Continuous variable

A variable (such as age, test score, or height) that can take on a wide or infinite number of values.

What are parameters?

Characteristic that describes a population

Identify the dependent variable and independent (or quasi-independent) variable. A professor tests whether students perform better on a multiple‐choice or fill‐in‐the‐blank test format.

DV students perform IV fill in the blank test format

Scale of measurement for ordinal question

Does a larger number indicate a greater value than a smaller number

Scale of measurement for ration question

Does dividing (or taking the ratio of) two numbers represent some meaningful value

Scale of measurement for difference question

Does subtracting 2 numbers represent some meaningful value

Identify the dependent variable and independent (or quasi-independent) variable. A health researcher tests whether the number of calories in a meal changes liking for that meal among a sample of adults.

IV number of calories DV liking for that meal

Ratio scale of measurement

Highest form of measurement and meets all of the rules of other forms of measurement; -mutually exclusive categories -exhaustive categories -ordered ranks -equally spaced intervals -a continuum of values

Identify the dependent variable and independent (or quasi-independent) variable. A social scientist tests whether attitudes toward morality differ based on political affiliation (Democrat or Republican).

IV political affiliation (Democrat or Republican) DV attitudes toward morality

Identify the dependent variable and independent (or quasi-independent) variable. A cultural researcher tests whether individuals from different cultures share or differ in the belief that dreams have meaning.

IV individuals from different cultures DV the belief that dreams have meaning.

What scale of measurement can be used for equal units?

Interval and ratio

An education counselor records the number of high school graduates enrolled in community colleges, four-year colleges, and universities. What scale of measurement is the type of college? A) nominal B) ordinal C) interval D) ratio

Nominal

Example of continuous classification

Olympic sprinters time to finish race, duration of drug abuse, score (0-100%) on an exam, temperature, age, weight

Ordinal scale of measurement

Order/ranking imposed on categories Numbers must preserve order 1 = Tallest 2 = Second tallest 3 = Third tallest

Researcher A measures academic preparedness as the percentage correct responses on an entrance exam; Researcher B measures preparedness as the current class rank of students. Which researcher measured academic preparedness as discrete data? A) Researcher A B) Researcher B C) both researchers D) no researchers

Researcher B

How to setup a research study

Select participants and create groups (2 groups drink grapefruit juice, one with and one without sugar)

Discrete classification

Separate and indivisible categories, whole numbers only

Examples of discrete classification

Socioeconomic class, gender, ranking of favorite foods, letter grade, body type (slim, average, heavy), ratings of satisfactions (1 to 5)

E(x-M)^2

Sum of the squared differences of scores

E(x-M)=0

Sum of thee differences of scores

Dependent Variable (DV)

The measured outcome (response) of a study

Dependent variable

Variables that were measured when IVs are manipulated (presumed effect)

Quantitative classification

Varies by amount, measured numerically and often collected by measuring or counting; continuous and discrete variables (ratings of satisfaction (1 to 5), height, weight)

Qualitative classification

Varies by form or class, often represented as a label and describes nonnumeric aspects of phenomena, only discrete variable, correspond to nominal scales, ordinal scale variable is typically qualitative but can also be quantitative

Continuum of values

a continuous series of elements or items that vary by such tiny differences that they do not seem to differ from each other. Example: a range of temperatures

Ogive

a graph that represents the cumulative frequencies for the classes in a frequency distribution

Variable

a numerical characteristic or condition that varies or has different values for different individuals (gender, GPA, etc)

Descriptive stats are procedures used to A) summarize a set of scores or observations B) organize a set of scores or observations C) make sense of a set of scores or observations D) all of the above

all of the above

Central tendency

average

_____________ are measured along a continuum at any place beyond the decimal point A) continuous data B) discrete data C) qualitative data D) open-ended data

continuous data

A researcher measures the body temperature (in degrees Fahrenheit) of participants immediately before and immediately following sleep. Temperature is on what scale of measurement? A) nominal B) ordinal C) interval D) ratio

interval

What scale of measurement can be used for differnce?

interval and ratio

How does randomization help experiments?

it helps minimize potential impact of irrelevant factors allowing us to attribute the observed outcome differences to the treatment variables

What happens to the mean if you add or take away a score?

it will change it unless the value equals the mean

What is important when constructing a frequency distribution?

make sure you could the number and dont just subtract because it will be wrong

Continuous classification

measured along a continuum, measured at any place beyond the decimal point

What is data?

measurements or observations

Nominal used for

naming, labeling, grouping, categorizing (dog-1, cat-2), cannot do math on these numbers

Scales of measurement

nominal, ordinal, interval, ratio

State the four scales of measurement in order from lease informative to most informative

nominal, ordinal, interval, ratio

Quantitative variables

numerical and can be ordered or ranked

Parameter

numerical descriptor of population, denoted by greek letters

Sample statistic

numerical descriptor of sample, denoted by latin letters (M, SD, etc)

Ordinal scale

numerically equal distances on the scale do not necessarily represent equal distances on the dimension underlying the scale (differences between 1 and 2 are not equally distant) (no arithmetic operations on the numbers can be performed)

A consultant ranks the five most needed areas of improvement for a local business. What scale of measurement are the rankings?

ordinal

Types of scales of measurement

ordinal, interval, ratio

Relative percent

percentage of scores that occurred in an interval

Each of the following is an example of quantitative data except A) weight in ounces B) income in dollars C) political affiliation D) age in years

political affiliation

Data for population are called?

population parameters

___________ data describe numeric aspects of phenomena; whereas ___________ data describe nonnumeric aspects of data

quantitative, qualitative

Types of research methods

quasi-experimental, correlational, experimental

Three key elements of control that allow researchers to draw cause-and-effect conclusions

randomization, manipulation, comparison/control

What scale of measurement can be used for absolute zeros?

ratio

What are scales of measurement used for?

to determine the type of statistical analyses possible

How does the scientific research process begin?

with a question or statement that can only be answered or addressed by making an observation

What is the sum of the differences of scores from their mean?

zero