Experimental Design Learning Objectives At the end of this lecture, - - PowerPoint PPT Presentation
Section 1.3 Introduction to Experimental Design Learning Objectives At the end of this lecture, the student should be able to: State the steps of conducting a statistical study. Select one step of developing a statistical study, and
At the end of this lecture, the student should be able to:
state the reason for this step.
a survey, and give an example.
Terms you Need to Know
conducting a statistical study
terms
from healthcare
1. State a hypothesis.
1. State a hypothesis. 2. Identify the individuals of interest.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data. 7. Use descriptive or inferential statistics to answer your hypothesis.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data. 7. Use descriptive or inferential statistics to answer your hypothesis. 8. Note any concerns about your data collection or analysis
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data. 7. Use descriptive or inferential statistics to answer your hypothesis. 8. Note any concerns about your data collection or analysis
causes asthma in children who live in urban settings
urban settings
and asthma
A person whom goes by the name Imagere
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data. 7. Use descriptive or inferential statistics to answer your hypothesis. 8. Note any concerns about your data collection or analysis
dataset
for population measures
Photo courtesy of US Army Africa.
dataset
for population measures
estimates
approach
found to be “human research”
to collect data about children
Photo courtesy of US Army Africa.
dataset
for population measures
estimates
approach
found to be “human research”
to collect data about children
Photo courtesy of US Army Africa.
1. State a hypothesis. 2. Identify the individuals of interest. 3. Specify the variables to measure. 4. Determine if you will use the entire population or a sample.
5. Address ethical concerns before data collection. 6. Collect the data. 7. Use descriptive or inferential statistics to answer your hypothesis. 8. Note any concerns about your data collection or analysis
In a census, measurements or
population are used. In a sample, measurements or
population are used.
Photo courtesy of Che/Wikimedia Commons Photo courtesy of Sandstein/Wikimedia Commons
Experiment Experiment
is deliberately assigned to the individuals
possible effect of the treatment or intervention on the variables measured
Photo courtesy of US Marines.
Experiment Experiment
is deliberately assigned on the individuals
possible effect of the treatment or intervention on the variables measured
Obser Observa vational tional Study Study
measurements of individuals are taken
intervention is assigned by the researcher
Experiment (wit Experiment (with h OS) OS)
Women’s Health Initiative
Experiment (wit Experiment (with h OS) OS)
Women’s Health Initiative
Obser Observa vational tional Study Study (OS (OS)
Nurses Health Study
replicated.
experiments is necessary for science to progress.
Photo courtesy of Neils B.
followed in order when conducting a statistical study.
determine the type of study, and make other study-related decisions.
Important Concepts
and administration minimize “bias”
Photo by Revital9
survey, the people who do complete it are likely to have a biased opinion.
do not complete your survey that has to do with how they feel about your survey topic.
Photo by Shay of Belfast, Northern Ireland.
happened a long time ago
happened since original event
response.
you agree with Obamacare?
person and phone surveys
from same population as research participant
influences matter
Photo by UK Department for International Development.
waiting room, ask the number of minutes.
important, how important is having a controllable lifestyle to you in your future career? A controllable lifestyle is defined as one that allows the physician to control the number of hours devoted to practicing his/her specialty.
condition, but may not cause that condition.
all make the same income.
the Department of Labor, these variables can decrease a person’s income at the same level of education.
women and African Americans make less money on the whole is not explained by fewer of them working, or fewer of them getting degrees.
these lurking variables.
Photo of Jackie Lacey, Los Angeles County District Attorney, by Neon Tommy..
important for improving healthcare and the progression of science.
special attention to avoiding bias in the design and conduct of surveys.
Definitions & Terms
assign individuals to treatment groups.
selecting members for each group.
variables” evenly
Image courtesy of Svjo.
Recruit sample
Recruit sample Measure confounders,
Recruit sample
Image courtesy of Wirelizard.
Measure confounders,
Recruit sample Group A Treatment
Image courtesy of Wirelizard.
Group B Placebo Measure confounders,
Recruit sample Group A Treatment
Image courtesy of Wirelizard.
Group B Placebo Measure confounders,
Measure confounders,
no treatment, but participant assumes s/he is receiving treatment and responds favorably.
group, which receives the placebo (or attention control if treatment is not a drug).
group.
Image courtesy of the National Institutes of Health
in two randomized groups, create “blocks” with two slots – one for a man, and one for a woman.
XXX Man Woman XXX Block 1 XXX Man Woman XXX Block 2 XXX Man Woman XXX Block 3 XXX Man Woman XXX Block 4
in two randomized groups, create “blocks” with two slots – one for a man, and one for a woman.
the study and you measure them, assign them to blocks.
ABC Man Woman XYZ Block 1 MNO Man Woman NFW Block 2 JKL Man Woman MMW Block 3 BBJ Man Woman MNL Block 4
in two randomized groups, create “blocks” with two slots – one for a man, and one for a woman.
the study and you measure them, assign them to blocks.
will get a paired couples in each group!
ABC Man Woman XYZ Block 1 MNO Man Woman NFW Block 2 JKL Man Woman MMW Block 3 BBJ Man Woman MNL Block 4
in two randomized groups, create “blocks” with two slots – one for a man, and one for a woman.
the study and you measure them, assign them to blocks.
will get a paired couples in each group!
ABC Man Woman XYZ Block 1 MNO Man Woman NFW Block 2 JKL Man Woman MMW Block 3 BBJ Man Woman MNL Block 4 Group A Group B
staff) is deliberately not told of a treatment assignment in a study so s/he is not biased in reporting study information.
Image courtesy of U.S. Marines
staff) is deliberately not told of a treatment assignment in a study so s/he is not biased in reporting study information.
treatment group when looking at images during study procedures.
Image courtesy of U.S. Marines
staff) is deliberately not told of a treatment assignment in a study so s/he is not biased in reporting study information.
treatment group when looking at images during study procedures.
not know treatment assignment.
Image courtesy of U.S. Marines
reduce bias in an experiment.
can even out groups.
bias
necessary to take into account.
Photograph by US Navy
Photo by photosteve101