Chp.1 quiz Flashcards
(22 cards)
A study is conducted to determine if there is a relationship between stomach cancer and alcohol consumption. Everyone treated at a hospital for stomach cancer was asked about their alcohol consumption. Is this an observational study or experimental study?
The study is an observational study because the study examines individuals in a sample, but does not try to influence the response variable.
Microsoft selects every 14th software Cd that comes off the assembly line starting with the third until she obtains a sample of 60 software CDs. What sampling is this?
Systematic sampling.
What is a cross-sectional study?
Cross-sectional studies are observational studies that collect information about individuals at a specific point in time, or over a very short period of time.
What is a case-control study?
are observational studies that are retrospective, meaning that they require individuals to look aback in time or require the researchers to look at existing records.
What is superior observational study?
Neither study is always the superior to the other. Both have advantages and disadvantages that depend on the situation.
Depot randomly select 110 store during a certain week and surveys all customers present in the store. What sampling is this?
Cluster
Nation of origin. Is this qualitative or quantitative?
Qualitative because it is an attribute characteristic
a poll of 2000 students in a high school found that 94% of its students owned cell phones. Parameter or statistic?
Parameter, because the data set of all 2000 students in a high school is a population.
Define statistic
Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. In addition statistics is about providing a measure of confidence in any conclusions.
What is an observational study?
measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.
What is a designed experiment?
when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group.
What does confounding mean?
study occurs when the effects of two or more explanatory variables are not separated. Therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable or variables not accounted for in the study.
What is lurking variable?
is an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study. In addition, lurking variable are typically related to explanatory variables in the study.
What is a confounding variable?
is an explanatory variable that was considered in a study whose effect cannot be distinguished from a second explanatory variable in the study.
What does it mean for the experiment to be placebo-controlled?
The experiment will have a control group that takes a placebo, which is a innocuous medication, such as sugar tablet. his control group serves as a baseline treatment that can be used to compare to the group that is actually taking the medication
What is a double-blind experiment?
Neither the subject nor the researcher knows which treatment the subject is receiving.
What is a randomized experiment?
the subjects are randomly assigned to take either the topiramate or the placebo
Miranda divides up her day into three parts: morning, afternoon, and evening. She then measures her power usage at 3 randomly selected time during each part of the day. What type of sampling is this?
Stratified
The average age of men who had walked on the moon was ( 39 years, 11 months, 15 days.) Is the value in parenthesis a parameter or a statistic?
value is parameter because the men who had walked on the moon are a population.
Age is a qualitative or quantitative variable?
Quantitative variable because it is a numerical measure
Length of time to finish a crossword puzzle: discrete or continuous?
Continuous because it is not countable
Fifty patients with heart arrhythmia are divided into two groups . One group receives a new drug to regulate heart rhythm, the other a placebo. After one month, the presence of arrhythmia is measured. Is this an observational or experimental study?
Experiment because the researchers control one variable to determine the effect on the response variable.
