Stat 503 Exam Questions And
Answers A+ Pass
why do we need statistics? - Answer- - biologists study the properties of living things
- measuring these properties is a challenge
variation - Answer- an inherent component of all living systems
system - Answer- anything composed of multiple interacting parts
constraints of stats - Answer- time and funding
uncertainty - Answer- variation + incomplete information
- sampling can bring it to the project
- probability or likelihood
Statistics - Answer- - the study of methods to describe and measure aspects of nature
from samples
- a branch of science chiefly concerned with the collection, analysis, interpretation, and
presentation of empirical data
- provides tools to turn raw data into knowledge and understanding
- helps us recognize and describe the patterns in our data and helps us decide how
certain we are that our data reflect reality
- it is about estimation
estimation - Answer- the process of inferring an unknown quantity of a population using
sample data
- a.k.a. statistic
- a related quantity calculated from a sample
- approximation of the truth
parameter - Answer- a quantity describing a population
- the truth
- The numeric quantities that we use to describe a distribution
model - Answer- a simplified representation of some part of the real world
sampling theory - Answer- focuses on the generalizability of descriptive findings to the
population from which the sample was drawn
- a good way to organize data collection
- ensures that our data are unbiased, so they give us a reliable picture of the real world,
and it also helps us to do this in a way that's efficient
, inferential statistics - Answer- numerical data that allow one to generalize- to infer from
sample data the probability of something being true of a population
statistical model - Answer- - estimate values
- test hypothesis
- predict new observations
- If we combine the parameters for location and spread of a distribution with an equation
that describes its shape
Biological, or scientific models - Answer- - explain how we think a system works
- They identify the important components in a system and describe how those parts
interact with each other
- they describe causal relationships among the different parts of the system
- Because these models propose specific cause-and-effect relationships, they can make
specific, testable predictions about the patterns that we should see in our data if they're
correct.
statistical models - Answer- - describe and summarize the patterns that exist in our
data, and explain how sampling error or other sources of random variation would affect
those patterns.
- As a result, they allow us to draw reliable or valid conclusions about patterns that exist
in the real world despite the fact that we are only looking at a small number of
individuals.
- Describe and summarize the patterns in data.
- Explain the effects of sampling error and other sources of random variation on those
patterns.
- Allow us to draw reliable (valid) conclusions about patterns that exist in the real world
based on limited data sets.
Statistical vs Biological - Answer- So statistical models are tools that we use to
determine whether we think that the patterns that exist in the real world match the
patterns that our biological models predicted. When we do this, we're making something
called an inference.
study population - Answer- the collection of all individual units that we want to draw
conclusions about
sample - Answer- - a smaller group
selected from the population, that
we actually observe and collect data on
- a subset of units taken from the population
sample units (study units) - Answer- The members of a population
specimen - Answer- a biological sample
Answers A+ Pass
why do we need statistics? - Answer- - biologists study the properties of living things
- measuring these properties is a challenge
variation - Answer- an inherent component of all living systems
system - Answer- anything composed of multiple interacting parts
constraints of stats - Answer- time and funding
uncertainty - Answer- variation + incomplete information
- sampling can bring it to the project
- probability or likelihood
Statistics - Answer- - the study of methods to describe and measure aspects of nature
from samples
- a branch of science chiefly concerned with the collection, analysis, interpretation, and
presentation of empirical data
- provides tools to turn raw data into knowledge and understanding
- helps us recognize and describe the patterns in our data and helps us decide how
certain we are that our data reflect reality
- it is about estimation
estimation - Answer- the process of inferring an unknown quantity of a population using
sample data
- a.k.a. statistic
- a related quantity calculated from a sample
- approximation of the truth
parameter - Answer- a quantity describing a population
- the truth
- The numeric quantities that we use to describe a distribution
model - Answer- a simplified representation of some part of the real world
sampling theory - Answer- focuses on the generalizability of descriptive findings to the
population from which the sample was drawn
- a good way to organize data collection
- ensures that our data are unbiased, so they give us a reliable picture of the real world,
and it also helps us to do this in a way that's efficient
, inferential statistics - Answer- numerical data that allow one to generalize- to infer from
sample data the probability of something being true of a population
statistical model - Answer- - estimate values
- test hypothesis
- predict new observations
- If we combine the parameters for location and spread of a distribution with an equation
that describes its shape
Biological, or scientific models - Answer- - explain how we think a system works
- They identify the important components in a system and describe how those parts
interact with each other
- they describe causal relationships among the different parts of the system
- Because these models propose specific cause-and-effect relationships, they can make
specific, testable predictions about the patterns that we should see in our data if they're
correct.
statistical models - Answer- - describe and summarize the patterns that exist in our
data, and explain how sampling error or other sources of random variation would affect
those patterns.
- As a result, they allow us to draw reliable or valid conclusions about patterns that exist
in the real world despite the fact that we are only looking at a small number of
individuals.
- Describe and summarize the patterns in data.
- Explain the effects of sampling error and other sources of random variation on those
patterns.
- Allow us to draw reliable (valid) conclusions about patterns that exist in the real world
based on limited data sets.
Statistical vs Biological - Answer- So statistical models are tools that we use to
determine whether we think that the patterns that exist in the real world match the
patterns that our biological models predicted. When we do this, we're making something
called an inference.
study population - Answer- the collection of all individual units that we want to draw
conclusions about
sample - Answer- - a smaller group
selected from the population, that
we actually observe and collect data on
- a subset of units taken from the population
sample units (study units) - Answer- The members of a population
specimen - Answer- a biological sample
