Research: Purpose, Method, and Questions

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Questions and Answers

Which of the following is the PRIMARY purpose of research?

  • To make a sound judgment
  • To develop new knowledge
  • To gather information
  • All of the above (correct)

What is the correct order of steps in the scientific method?

  • Ask a question, make a hypothesis, background check, test with experiment, analyze data, communicate results.
  • Ask a question, background check, make a hypothesis, test with experiment, analyze data, communicate results. (correct)
  • Make a hypothesis, background check, ask a question, test with experiment, analyze data, communicate results.
  • Background check, ask a question, make a hypothesis, test with experiment, analyze data, communicate results.

What is the PRIMARY role of a research question in a study?

  • To outline the expected results of the study
  • To provide a broad overview of the topic
  • To identify the phenomenon to be studied (correct)
  • To satisfy ethical requirements.

Which of the following characteristics is NOT typically associated with a good research question?

<p>The question is broad (D)</p> Signup and view all the answers

In the PICO framework, what does the 'I' stand for?

<p>Intervention (D)</p> Signup and view all the answers

Which type of research is primarily focused on hypothesis generation, with data gathered through ideas?

<p>Qualitative (B)</p> Signup and view all the answers

How does inductive reasoning proceed in qualitative research?

<p>From specific observations to general theories (D)</p> Signup and view all the answers

Which reasoning type starts with a theory and moves to confirming it?

<p>Deductive reasoning (C)</p> Signup and view all the answers

In research, what distinguishes theory generation from theory testing?

<p>Theory generation focuses on ideas while theory testing focuses on numerical data. (A)</p> Signup and view all the answers

Which type of research is MOST suitable for identifying cause-and-effect relationships?

<p>Experimental research (C)</p> Signup and view all the answers

What does 'dependent variable' measure?

<p>A variable that is measured (B)</p> Signup and view all the answers

How are participants typically assigned to groups in a true experimental design?

<p>Randomly (A)</p> Signup and view all the answers

What is a key characteristic of quasi-experimental designs?

<p>Testing causality with suboptimal variable control. (C)</p> Signup and view all the answers

What is the primary purpose of a 'control group' in experimental research?

<p>To serve as a baseline for comparison (A)</p> Signup and view all the answers

According to the information given, which statement provides the MOST accurate definition of ethics in research?

<p>Moral principles that guide a person's behavior or the conduct of an activity (B)</p> Signup and view all the answers

Which ethical principle emphasizes an individual's right to make informed decisions?

<p>Respect for persons (B)</p> Signup and view all the answers

What is the purpose of debriefing in studies involving deception?

<p>To provide participants information about the true purpose of the study. (C)</p> Signup and view all the answers

What is the purpose of the 'literature review' section in a research paper?

<p>To summarize information on what has already been investigated in the field. (A)</p> Signup and view all the answers

What is the CRAAP test primarily used for?

<p>To evaluate the credibility of information sources (B)</p> Signup and view all the answers

Which of the following BEST describes a 'concrete variable'?

<p>A variable easy to define, measure, and manipulate (D)</p> Signup and view all the answers

What is the MAIN purpose of an operational definition in research?

<p>To specify the exact usage of a term or variable in a study. (A)</p> Signup and view all the answers

Which measurement scale allows one to determine the difference, direction of difference, and equality of units, but does not have an absolute zero point?

<p>Interval scale (C)</p> Signup and view all the answers

Which scale possesses a true zero point?

<p>Ratio (A)</p> Signup and view all the answers

Which of the following statements is TRUE regarding nominal data?

<p>Numerical labels are used, though measuring differences is impossible (C)</p> Signup and view all the answers

What is a key assumption of parametric statistics?

<p>Often assumes data is independent (A)</p> Signup and view all the answers

What characterizes non-parametric statistics?

<p>Relies on few assumptions about underlying population parameters (D)</p> Signup and view all the answers

What is the difference between a population and a sample?

<p>A sample is a smaller group of participants that is representative of the population (D)</p> Signup and view all the answers

What does 'random assignment' accomplish in experimental design?

<p>Helps to ensure equivalent groups at the start of a study by preventing bias. (D)</p> Signup and view all the answers

What is the key characteristic of qualitative sampling?

<p>Participants are selected for specific characteristics (B)</p> Signup and view all the answers

What is 'snowball sampling'?

<p>Participants refer the researcher to other potential participants (A)</p> Signup and view all the answers

What is a key advantage of using self-report in data collection?

<p>It measures how people think and report how they feel, act, think (D)</p> Signup and view all the answers

What does a 'loaded question' contain?

<p>A question that contains unproved assumption or emotionally laden term (B)</p> Signup and view all the answers

What is the process of breaking down data into codes or labels?

<p>Open coding (D)</p> Signup and view all the answers

Which of the following BEST describes a 'Quantitative variable'?

<p>A variable for which for which the numic score represent a change in quantity (D)</p> Signup and view all the answers

Flashcards

Research Cycle

A method that systematically investigates a question through a specific plan or procedure, collecting and analyzing data, and disseminating information.

Scientific Method

A series of steps used to gain knowledge. It includes asking a question, doing background research, forming a hypothesis, testing with experiments, analyzing data, drawing conclusions, and communicating results.

Research Question

A statement identifying the specific phenomenon to be studied. It focuses the study, determines methodology, and guides all stages of inquiry, analysis, and reporting.

Good Research Question

A good research question is feasible, clear, significant (substantial and original), and ethical.

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PICO

Population, Intervention, Control, Outcome--used to create research questions.

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Quantitative Research

Confirm the hypothesis, focuses on numeric data, predetermined variables.

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Qualitative Research

Generates a hypothesis, depth via ideas, research evolves.

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Qualitative Worldview

Knowledge is developed by examining patterns in people's words, actions, and records.

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Qualitative Reality

Reality is subjective and contextual.

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Inductive Approach

Reasoning moves from specific to general.

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Quantitative Knowledge

Knowledge comes from empiricism and rationalism.

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Quantitative Reality

Reality is objective and measurable.

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Deductive Approach

Reasoning moves from general to specific.

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Descriptive Research

Used to describe patterns and generate understanding.

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Predictive Research

Used to identify factors that predict relationships; correlation, not causation.

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Experimental Research

Cause and effect by manipulating variables.

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Dependent Variable

Variable that is measured in a study.

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Independent Variable

Variable that is manipulated in a study.

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True Experimental Design

Random assignment, true manipulation.

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Quasi-experimental Design

Lacks full variable control, non-random assignment.

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Ethics

Moral principles governing behavior.

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Research Ethics

Researchers protect participants.

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Informed Consent

Free choice, informed, ongoing.

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Concern for Welfare

Protect lives, confidentiality, minimize risk.

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Deception in Research

Lying to participants; alter behavior.

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Debrief

After deception, fully explain purpose.

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Abstract

Overview: intro, methods, findings, conclusion.

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Introduction Section

Establishes topic and fills literature gap.

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Literature Review

Discusses/analyzes existing research.

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Measurement Scales

NOIR scales are nominal, ordinal, interval and ratio.

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Operational Definition

Specifies variable use in a study.

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Nominal Scale

Differences are named categories.

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Ordinal Scale

Differences are categories with order.

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Interval Scale

Equal units, direction and equality.

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Ratio Scale

The scale has an absolute zero.

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Study Notes

Purpose of Research

  • Research includes gathering information, making sound judgments, and developing new knowledge.
  • The research cycle systematically progresses from a question, to a plan, to data collection/analysis, and finally information dissemination.

Scientific Method Steps

  • The scientific method involves asking a question, followed by a background check.
  • A hypothesis is then formulated and tested through experiments.
  • The procedure is refined, if necessary, through repeated experimentation.
  • Data is analyzed, conclusions drawn, and if the conclusions do not align with the initial hypothesis, a new research question is developed based on gained knowledge.
  • Results are communicated.

Research Question

  • A research question is a statement identifying the phenomenon to be studied.
  • It focuses the study, determines the methodology, and guides all stages of inquiry, analysis, and reporting.

Characteristics of a Good Research Question

  • A good research question is feasible, clear, significant (substantial and original), and ethical.

PICO: Creating a Research Question

  • PICO helps to create a research question.
  • Population considers patients/population.
  • Intervention is the exposure to be considered.
  • Control involves a control group (baseline, comparison treatment).
  • Outcome looks at the outcome of interest and effect of intervention.

Research Paradigms

  • Qualitative methods are wordy.
  • Quantitative methods use numbers.

Types of Research

  • Quantitative research confirms a hypothesis through numbers, with predetermined research design and variables.
  • Qualitative research generates a hypothesis through gathered ideas, with an evolving research design and variable.

Approaches to Research: Qualitative vs. Quantitative

Worldview of Knowledge

  • Qualitative research develops knowledge by examining patterns of meaning in people's words, actions, and records.
  • Quantitative research develops knowledge through a collaboration of empiricism and rationalism.

Nature of Reality

  • In qualitative research, reality is subjective and contextual.
  • In quantitative research, reality is objective and can be known.

Approach

  • Qualitative research uses inductive reasoning, moving from the specific to the general.
  • Quantitative research uses deductive reasoning, moving from the general to the specific.

Steps in Reasoning

  • Qualitative reasoning involves observing specific behaviors, identifying specific patterns, formulating a proposed hypothesis, and developing a conclusion, model, or theory.
  • Quantitative reasoning starts with a theory, develops a specific hypothesis to test, collects observations to confirm or refute the hypothesis, and then confirms the theory.

Data

  • Qualitative research uses ideas.
  • Quantitative research uses numerical data.

Research Approach

  • The research design and variables evolve in qualitative research.
  • Research design and variables are predetermined in quantitative research.

Methods of Research

  • Descriptive research involves observation to describe and understand patterns, including surveys, observational studies, epidemiological studies, and case studies.
  • Predictive research identifies factors to predict relationships, often using correlation, but this does not imply causation.
  • Experimental research identifies cause and effect factors through true, quasi, or pre-experimental designs.
    • Dependent variables are measured.
    • Independent variables are manipulated.

Variables

  • Variables are entities that can take on different values.
  • Independent variables are manipulated.
  • Dependent variables are measured.

True Experimental Design

  • Participants are randomly placed into groups.
  • The manipulated variable is true.
  • Eligibility is assessed, and participants are allocated to intervention, receive intervention, and are followed up for analysis.

Quasi-Experimental Design

  • Causality is tested with suboptimal variable control.
  • Participants are placed into groups non-randomly.
  • Group subjects are based on a participant variable.

Experimental Research

  • The control group represents the baseline.
  • The experimental group may changed due to the independent variable.

Experimental Research (Cause and Effect)

  • Pre-experimental designs have very little control group.
  • Quasi-experimental designs often have a control group.
  • True experimental designs always have a control group.
  • Random selection of subjects from the population is absent in pre- and quasi-experimental designs, but present in true experimental designs.
  • Random assignment of subjects to groups is absent in pre- and quasi-experimental designs, but present in true experimental designs.
  • Random assignment of intervention to groups is absent in pre-experimental designs, sometimes present in quasi-experimental designs, and always present in true experimental designs.

Ethics

  • Ethics are moral principles governing a person’s behavior or activity.
  • The Code of Nuremberg (1949) is a ten-point statement outlining medical research on humans.
  • Research is only justified if it is socially beneficial and conducted in a manner that satisfies moral, ethical, and legal concepts.
  • The Declaration of Helsinki (1964) developed by the World Medical Association, is a main ethical statement in research articles today.
  • The Declaration's main focus is on identifiable human data.

Research Ethics in Canada

  • Researchers are responsible for the welfare of participants.
  • Most journals require an ethical approval statement.
  • Research Ethics Boards or Institutional Review Boards are required.
  • Canada has three federal agencies: the Canadian Institute of Health Research, the Natural Sciences and Engineering Research Council of Canada, and the Social Sciences and Humanities Research Council.
  • The Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans, covers consent, conflicts of interest, data privacy/confidentiality, native status, and human biological/genetic research.

Core Principles

  • Respect for persons includes respecting autonomy by providing the opportunity to deliberate about decisions
  • Ensuring free, informed, and ongoing consent with free choice (voluntary), informed choice, and ongoing choice.
  • Protect individuals with developing, impaired, or diminished autonomy with adequate information without coercion.
  • Concern for welfare involves protecting a person’s quality of life in all aspects, including physical, mental, and spiritual health.
  • Privacy and confidentiality must be ensured.
  • Risks should be minimized and beneficence should be maximized.
  • Accurate and accessible information should be provided.
  • Justice includes fairness in treating people and equality in the distribution of research benefits and burdens.
  • Deception involves lying about the true nature of a study because knowing the truth may alter behavior.
  • Blinding uses a placebo.
  • Debriefing is critical in studies with deception; researchers should provide information about the study's true purpose.
  • Nutrition research in Indigenous communities has included nutrition experiments in residential schools, control vs. treatment groups of malnourished kids, and no consent.

Anatomy of a Research Paper

  • The abstract provides an overview, including introduction/background, problem statement, methodology, findings, and conclusion.
  • The introduction introduces the general topic, background, and previous research, and fills in the literature gap, as well as the purpose of the research statement, primary and secondary objectives.
  • The literature review commonly is continued from the introduction, provides information on what has been investigated, can provide slight critiques, and rewrites the gap and why it’s important.
  • The methodology outlines the research design, population, recruitment methods, measurement details, and analysis.
  • The results section states relevant findings, demographics, completion and drop-out rate, outcomes specific to the study, without interpretation, and uses graphics.
  • The discussion reviews findings, discusses outcomes, states the importance of the project, interprets findings, links the findings to literature, provides potential reasons for the outcomes, strengths, limitations, and future directions.
  • The conclusion reiterates the study with main findings and importance, providing a concluding sentence about what should be done next and why without new data.
  • Acknowledgements recognize contributions made by others who aren’t given authorship.
  • Includes a list of references.
  • Authors are listed by way of contribution.

CRAAP Test

  • CRAAP (Currency, Relevance, Authority, Accuracy, Purpose) test is a method of determining the reliability of information included in the research.
  • Currency indicates the timeliness of the information.
  • Relevance refers to how relevant the information is in relation to the research.
  • Authority refers to who the authors, sponsors, publishers, and sources are.
  • Accuracy indicates the reliability, truthfulness, and correctness of content.
  • Purpose describes the purpose or intent of the information.

Measurement Variables

  • Focus: designing and conducting the study
  • What data do we want to collect?
  • How will we collect this data?

Research Variables

  • Examples include height, weight, age, gender, scores on test, income, and birthplace.
  • Concrete variables are easy to define, measure, and manipulate.
  • Non-concrete variables have definitions and ways of measuring that are not obvious.
  • All variables need to be operationally defined.

Operational Definitions

  • Operational definitions specify the exact usage of a term in a study.
  • They should reflect common usage in the discipline and are required for words that have multiple meanings.

Measurement Scales: NOIR (Nominal, Ordinal, Interval, Ratio)

  • Non-parametric scales include nominal and ordinal.
    • Nominal scales indicate difference.
    • Ordinal scales indicate difference and direction of difference.
  • Parametric scales include interval and ratio.
    • Interval scales indicate difference, direction of difference, and equality of units.
    • Ratio scales indicate difference, direction of difference, equality of units, and absolute zero.

Identity (Nominal)

  • Each value has a unique meaning.

Magnitude (Ordinal)

  • There is a specific order to the variables.

Equal Intervals (Interval)

  • Data points along the scale are equal.

No Value of Zero (Ratio)

  • Scale has a true zero where no data point acts as a starting point.
  • Nominal = NAME (N & N)
  • Ordinal = ORDER (O & O) + NAME
  • Interval = INTERVALS (I & I) + NAME and ORDER
  • Ratio = RADICAL (Think “Ratio is radical because it has it all”) + NAME + ORDER + INTERVAL

Parametric Stats

  • Assumes data are normally distributed and follow a normal curve.
  • Assumes data from all groups have the same spread.
  • Assumes data are linear, with an example correlation.
  • Often assumes data is independent.
  • Linear correlation is on the graph.

Non-Parametric Stats

  • Rely on few or no assumptions about the shape of the curve or parameters of the underlying population.
  • Used in small sample sizes.
  • Used with non-normal distributions.
  • Not as affected by outliers.
  • Generally, not as statistically significant.

Discrete Data

  • Variables can assume only a finite number of real values within a given interval.
  • Represents whole numbers that cannot be divided or broken down into fractions/decimals.

Continuous Data

  • Variables can assume an infinite number of values.
  • Can be broken down into units, fractions, and decimals.

Sampling Procedures: Population vs. Sample

  • The population: all inclusive group of people that researchers generalize their findings to.
  • Defined by researchers.
  • A sample is a representative subset of the population that takes part in a study.

Representative Sample

  • The sample must be like the population.
  • Findings only relate to the group that was drawn.

Probability Sampling

  • Involves random selection.
  • In a simple random sample, odds are the same for everyone.
  • Systematic sampling: researchers use lists to select every nth (or any number) person.
  • Stratified random sampling: the population is divided into subgroups before randomization, ensuring subgroups are fairly represented, and then the population is ordered, followed by a random sample.

Non-Probability Sampling

  • Population does not have an equal chance of being drawn.
  • Findings may be generalized, but unlikely.
  • Convenience sampling: researchers recruit participants that are convenient to them for their time and place; they are mainly volunteers.
  • Quota: a certain number of participants are recruited.
  • Generalizability: can the findings from a sample be generalized to the population or outside of the lab or research setting.
  • Requires the reader to decide whether legitimate inferences or generalizations can be made.

Sample Size

  • Equations and computer software exists to determine size of sample.
  • Smaller sizes leads to type 2 errors.
  • Goal is to have more data.

Random Assignment

  • Also known as randomization.
  • How the sample is put into the treatment groups.
  • Important to prevent bias, and different treatment groups are equivalent.
  • Typically computer generated.

Qualitive Sampling

  • Generally, a sample is not taken from the population.
  • Participants are selected for characteristics.

Purposeful Sampling

  • Select sample from which the researcher can learn the most.
  • Analyze and data collection simultaneously.

Quota Sampling

  • Recruiting a certain number of participants with characteristics of interest, then finding people with the criteria until the quota is reached.

Snowball Sampling

  • Using chain referrals.
  • The participants refer the researcher to people they already have contact with who would satisfy the study's inclusion/exclusion criteria.
  • Useful for groups that are not easily accessible via other strategies.

Data Collection

  • Tools used in data collection.
    • Self-report: participants respond to the researcher's questions.
      • Measures how people think and report how they feel, act, think.
      • Can be quantitative or qualitative.

Question Delivery

  • Self-administered: low cost, chance for misinterpretation, low response rate.
  • Phone: higher response rate, higher cost, takes time, socially desirable response.
  • Personal Interview: high response rate, easy clarification, bad for cost and time, interviewer bias.

Question Style

  • Closed-ended: quantitative, participants must choose from a number of alternatives.
  • Rating scales: quantitative, participants must provide a rating.
  • Open ended questions: qualitative, asked to expand on answer.

Question Errors

  • Loaded questions: contains unproved assumption or emotionally laden term- makes respondent feel guilty/ shameful.
  • Leading questions: pushes an answer into the participants mouth and gives forced answers.
  • Double barreled questions: asks multiple things at once.

Interviews

  • Quantitative interviews are usually open-ended questions.
  • Typically recorded and transcribed, unless not feasible or too intrusive.

Question Types

  • Informal conversation interviews are unguided and most flexible, also hardest to summarized.
  • Semi-structured interviews are semi-guided.
  • Standard open-ended interview are completely structured, least flexible, easiest to summarize.

Test

  • Is an instrument used to assess individual differences in various content areas.
  • Possible problems- state of participant on given day and interpretation of results.

Behavioral Measures

  • Observation and recording of behaviors.
  • Possible problems- reactivity, observer accuracy.

Classifying the Observation

  • Participant vs non-participant: participating or not.
  • Disguised vs non-disguised- subjects aware or unaware.
  • Laboratory vs natural setting- control or realism.
  • Direct vs indirect- as it occurs/ active involvement or after the fact observation.

Case Study

  • Involves a research question, setting, and a study of some kind.
  • Measures of bodily activity, equipment, objectivity are also included.
  • Possible problems: equipment accuracy, conductor skill.

Data Types

  • Quantitative variables includes a numerical score, weight, age, VO2 max.
  • Qualitative variables includes categorical variables that may represent a discrete category- hair color, shoe preference, dog breed.

Organizing/Summarizing Data

  • Frequency distribution- information on number of observations for each variable.
    • All scores listed “f”= # of times each score occurs.
    • Show data pattern.
  • With Histograms the bars do touch each other to indicate data is related.
    • The X-axis order is specific.
    • Good for Ordinal, Interval, and Ratio data.
    • Appropriate for discrete and continuous data.
  • Frequency polygrams-can be expressed in frequency polygons. - Showcases data from cumulative frequency over time.
  • Bar graphs: the bars do not touch each other.
    • The X-axis order is not specific.

Validity and Reliability

  • Researchers are concerned with accuracy of measurement.
    • Accuracy of measurement- is it valid
    • Conisistancy- is it reliable
  • Validity: the extent to which a test measures what it is supposed to measure
    • It is a trait of the instrument
    • Needs only to be established once
    • Proper use of the instrument should yield truthful results
  • Types of Validity - Logical validity- weakest types and qualitatively: - Face validity: uses common sense approach, involving no statistics or numbers to express accuracy. - Content validity: use of written test/surveys, and a panel of experts that determine and assess logic and authoritativeness, with no values to express accuracy. - Statistical validity: - Criterion- based validity: - Concurrent: ability to estimate current performance, with used of a new measure to a gold standard, when 2 measures are obtained in close time proximity. - Predictive: Ability to predict future performance and the Event predicted is criterion measured and presented test is one to be evaluated.
    • Steps- -Develope an inventory of questions - Responses are score-based - Administer the questions to a representative sample who vary in smoking habits - Responce to the questions=score - Level of smoking= score - Statistically exime the degree of relationship between the two scores - Construct validity: Used when the variable has no definitive criterion, difficult to measure, can’t be directly observed
  • Reliability - Error in results can happen due to the participant, testing, scoring, and instrumentation. - Correlation can be used to determine the degree of reliability. - Values closer to 1 have less error. - Measures the consistency of scores/data. - Informs about the dependability of the test results. - Refers to the score/data and not the instrument. - Must be established when reporting reliability values.
  • Types of reliability. - External- comparing test - Internal- consistency of a test within itself

Measures of Central Tendency

  • Mean- average of the data set: sum of data set/ number of data.
  • Median- the middle of the data set: (n+1)/2.
  • Mode- the most frequently occurring

Measures of Variation

  • Range- the distance between the endpoints: highest score- lowest score.
  • Standard deviation- indicates how far the values stray from the mean.
    • Square to remove any negative values.
    • Take square root to remove the effect of squaring.

Normal Curve

  • Describes the overall shape of the distribution and range of a population mean,
  • Includes a method for visually displaying data

Distribution Shape

  • Kurtosis measures kurtosis and is identified by-
    • Shape of curve or tailedness.
    • How flat or peaked a normal curve appears.
  • Named forms included-
    • Mesokurtic- Distribution resembles the normal curve
    • Platykurtic- Tails are short and thin/ Negative kurtosis because of lower peak
    • Leptokurtic- Longer and fatter tails/ Positive kurtosis

Skewed Distributions

  • Involve many distributions that are not normally distributed.
    • These can present as scores that cluster, opposite the tail.
    • Or with possitively skewed distributions that has greater mean that median.
  • Others can offer Negative distributions for which the mean is less than the median

Descriptive Statistics

  • Measures of Central Tendency offer information about the middle of a data set.
  • Measures of Variability offer provide information about how spread out the data is.
  • Distribution shape provides information about whether the majority of the data clusters near the mean or spreads throughout the data set.

Z-Score

  • Measures skewness as the measure of the lack of symmetry of a data set and indicates a non-normal data distribution.
  • Can have negative- for the area under the curve from the mean.
  • Calculations involve: Z score- a measure of how many units a raw score is from the mean.
    • z=x-μ/ σ: x is the raw score, μ is the mean, and σ is the SD.
    • Positive scores above μ, negative scores under, 0 means the mean.

Percentile Rank

  • Score indicates % of those which are at or below the given raw score.

Hypothesis

  • Hypothisis : An educational guess with limited evidence as a starting point.
  • Hypothesis testing : The process of determining whether a hypothesis is supported by the results of research
    • A process that includes Accepting or rejecting study based on objective and logical stats and referring to the population.
  • Null hypothesis: Is defined as a statement that ther is no difference.
    • Generally assumed to be true, until proven.
    • Aim to see if the null hypothesis is true and the purpose of the research is to decide whether Null hypothesis is probable true or probably false.
  • Alternative hypothesis which Predicts that a significant difference exist between groups being compared for study. -Is Used when null is rejected. -One-tailed hypothesis: Includes research that predicts the direction of the expected difference between the groups.
  • Two-tailed hypothesis: researcher expects to find a difference between the groups, but does not predict the direction of that difference.

Hypothesis Testing Terminology

  • Ho: Default position, Generally assumed to be true until evidence indicates otherwise.
  • Ho is True Groups Truly the Same: Result "true negative".
  • Ho is False Groups Truly Different : Result "true positive".

Statistical Significance

  • Defines an differences is groups is unlikely to have occurred by chance, generally 5% alpha level. -Common misunderstandings: that the probability of true or false is not statistically signigicant.
  • Type one results are generally more serious. How to reduce both. -Reduce the alpha- level. -Increases the chance of making a type 2 error -Increase sample size to help.

Calculations in Testing and Power anlysis :

  • P-values, power, alpha, beta.
    • P-value is an also known as an alpha level,
    • Power = Inverse of beta(Power = 1-β), defined a the Probability of what must be 11.1 in test review?

confidence Intervals:

  • Confidence intervals(CIs) indicate the estimated range of values that is likely to include the unknown population parameter. -Population parameter: is defined as a Number that describes a fixed but unknown characteristic of the population. -Which indicates the Mean of your estimate +/- the variation of that estimate.
  • Confidence that indicates probability
    • Interval =range you expect your that shows estimate to fall between What makes for Confidence interval success: -Instead of estimating the parameter by a single value, use an interval that is likely to include the parameter given -Which provides A confidence interval that provides a lower limit and an upper limit that is likely to contain the true population parameter

Measuring and Identifying "X" Factors

To measure:

  • A 68% confidence interval to mean that there is a 68% chance that the calculated confidence interval contains the true population parameter
    • The Z factor is z* to use is 1.00
  • A 90% means the confidence interval contains a 90% chance that the calculated confidence interval contains the true population parameter.
    • In this The Z factor is z* to use is 1.645
  • A 95% indicates confidence is a 95% chance that the calculated confidence interval contains the true population parameter.
    • Here the z* to use is 1.96

Relationships Between Items"

A 99% that the confidence interval to mean contains has a a 99% chance that the calculation is related. -The Z is set to z* to use is 2.58 Reporting the findings;

  • The conclusion must Express the confidence level in percent with the lower limit(LL) and upper limit(UL)
    • To represent 95% CI [LL, UL]
  • Testing for Misconception: In the Event that When comparing two parameter estimates, -It is almost always true that the Cls do not overlap, then the result will be statistically significant or correct: -Is it not correct to assumes that if CIs do overlap, that the result is not statistically significantly

Establishing Correlation Between Items

  • Describes degree to which variables are linearly related(positive or negative) and potentially be used for predict(predictive validity).

    • Must be Used when impractical or unethical to do an experimental study
  • Test The null hypothesis that there is no relationship between the variables and find or establish the alternative hypothesis.

  • Correlation coefficient: uses the Pearson correlation coefficient and measures Measures of the correlation between 2 variables (interval or ratio scale) Which has a Relationship that is expressed as r, and which offers a R value that is measured from -1 to 1 and allows for Interpertation: -1 is strong 0 is no relationship +1 is strong, the 1's are perfect.

  • As "r" approaches As -1 or +1 there is an increases correlation between the two variables, -However you Can only tell us about linear relationships

Measuring Relationship Types

If r is found to be between 0 and 1 the Positive correlation is expressed in items changing in the same direction -Example: A puppy's length and weight; good customer service and sales; hours spent studying and exam grade; speed of wind turbine and energy produced If r= 0 there is a No correlation or no relationship, as seems in examples of, Amount of candy consumed and length of hair; Car speed and shoe size; running speed and toothpaste preference Between 0 and -1 this is a Negative correlation, which Suggests if one variable changes, the other will change in the opposite direction. An Example can be found in cases where Amount of exercise and blood pressure; a hen's age and number of eggs produced; caffeine consumed and perception of fatigue

Validity of strength in relationships:

  • The more the no relationship, the weaker the relationship.
  • As the relationship increases so to does the strength to the relationship: -0.761.00 = High -0.51-0.75=Fair -0.26-0.50=Moderate -0.00-0.25=None to weak * or curvilinear

When using Validity one must * Careful!!! and Graph results to make sure it is not curvilinear

  • Scattergrams/Scatterplots provides diagrammatic representation of the relationship between 2 variables, -With what gives a quick indication of relationship. It is Important to graph-relationship in case a non-linear relationships exists.

###Relationship types Positive -Where Variables move in same direction . -A rise to and increase (decrease) in one produces an increase(decrease) in the other. Negative

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