Term
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Definition
| the science of collecting, classifying, summarizing, organizing and interpreting data |
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Term
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Definition
the object upon which we
collect data. It is the source of
each “observation”.
In our water research, it is a
bit of water taken from a
segment of the brook at a
particular time. |
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Term
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Definition
a characteristic of the
experimental unit that is
measured from one
observation to the next.
In our water research, it could be concentration of nitrate |
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Term
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Definition
| a collection of data on all experimental units. The population is all possible observations. |
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Term
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Definition
| a subset of the population |
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Term
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Definition
| summarize the sample data |
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Term
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Definition
use the sample data to say something about the population
give a measure of reliability (i.e. precision, confidence) about the population parameters |
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Definition
| a list of all units in the population. |
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Term
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Definition
| every unit in the population has the same probability of being selected for the sample and the probabilities are independent |
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Term
| Stratified Random Sampling |
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Definition
| the population units are partitioned into strata, then simple random sampling is carried out in each stratum |
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Term
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Definition
| units are selected according to clusters |
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Term
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Definition
| every Kth element is selected |
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Term
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Definition
exists when some subset of the population has uneven and unaccounted for probability of selection
Non-response in surveys can be a type of bias |
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Term
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Definition
is the difference between the actual value of the variable and the recorded value of the variable. Measurement error can be a type of bias.
A faulty thermometer can produce measurement error |
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Term
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Definition
refers to the natural variation in any simple random sample.
Not mistake.
1.Bias + Sampling Error = the difference between reality and your observations = TOTAL ERROR
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Term
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Definition
–Mean is the average
–Median is the middle
observation of ordered data
•Definition is slightly different for
Odd n versus Even n
Mode is the value that occurs with the greatest frequency |
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Term
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Definition
–Range = Maximum minus
Minimum
–Variance
–Standard Deviation is square root of variance
•When the distribution is bell shaped:
–about 70% of observations are within one standard deviation of the mean
–about 95% of observations are within two standard deviations of the mean
–Inter-quartile range = 3rd Quartile minus 1st Quartile
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Term
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Definition
the value at which P% of the observations fall on or below and (100-P)% of the observations fall above
•Max is 100th percentile
•Third quartile is 75th percentile
•mid-quartile is 50th percentile, which is the median
•First quartile is 25th percentile
•Min is 0th percentile
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Term
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Definition
| Z-score = ( Xi – Xbar ) / s, where s is the standard deviation |
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Term
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Definition
•Candidates for outliers have z-scores less than –3 or greater than +3 |
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Term
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Definition
If the distribution is symmetric, then it is not skewed
If the tail of the distribution extends to the right, then the distribution is skewed right, i.e. skewed in the positive direction
If the tail of the distribution extends to the left, then the distribution is skewed left, i.e. skewed in the negative direction |
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Term
•Notation for population parameters and sample statistics on page 179 |
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Definition
–Mean
•Mu is parameter, Xbar is statistic
–Variance
•sigma2 is parameter, s2 is statistic
–Standard Deviation
•sigma is parameter, s is statistic
–Z-score
•z is parameter, z is statistic
–Correlation coefficient
•rho is parameter, r is statistic |
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Term
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Definition
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Term
Frequentist view of probability |
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Definition
–Probability is the number of times that an event happens divided by the number of trials |
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Term
Bayesian view of probability |
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Definition
| Probability is a person’s subjective judgment concerning the likelihood of an event, based on the information that the person has |
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Term
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Definition
is the process of making
observation(s) on unit(s)
–Selecting a card from a deck
–Flipping a thumbtack
–Observing the cloudiness of the sky
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Term
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Definition
the outcome of an experiment
–The card is red
–The thumbtack lands point up
–Sky is Clear
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Term
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Definition
the collection of all possible events
–Red Card or Black Card
–The thumbtack lands in the point up or point down position
–Sky can be: Clear, Few Clouds, Many Clouds, Other
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Term
Definitions illustrated by Venn diagrams |
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Definition
–Experiment, Event, Sample Space, Probability, Mutually exclusive events, Complement of an event, Conditional probability of A given B, Independent, Intersection, Union |
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Term
| The Probability of an event A |
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Definition
| denoted P(A) is a real number between 0 and 1 that indicates the likelihood that event A will occur when the experiment is performed. |
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Term
| The Complement of an event A |
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Definition
| denoted A´, is the event that A does not occur. |
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Term
| The Intersection of A and B |
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Definition
| the event that both A and B occur. |
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Term
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Definition
the event that A or B occur
1.P(A or B) = P(A) + P(B) – P(A and B)
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Term
| A and B are mutually exclusive events |
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Definition
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Term
| The probability of A given B |
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Definition
| denoted P(A|B), is P(A ∩ B)/P(B) |
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Term
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Definition
means P(A) = P(A|B) = P(A ∩ B)/P(B)
–Which implies that A and B are independent if and only if P(A ∩ B) = P(A) * P(B)
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