Karteikarten
Statistics 1
Karten in diesem Stapel (39)
- 1What is necessary to be able to interpret the presentation of the data and what they are displaying?Statistical analysis
- 2In veterinary what does statistics refer to?T
- 3What are the 2 ways you can lie with probability-based statistics?1. Start with false assumptions
2. - 4Why do we need to know about statistics?Evidence-Based Medicine - practice of medicine should be based on scientific evidence
- 5What are the 2 types of data?1. Quantitative - continuous or discrete
2. Categorical - ordinal or nominal - 6What is nominal data?There isn't a category between categories. They aren't inherently ranked.
eg. gender, species, country - 7What is ordinal data?There is a order to which data goes but it is a complete integer.
eg. rank 3>4>5 or birth order in a litter - 8What are 2 things you should do as a general rule before carrying out any statistical calculations?1. Explore the data graphically or in a table
2. Think of a meaningful and useful way to display the data - 9Give 4 uses for graphs.1. Identify the general shape of the data including the centre of its distribution and how variable it is.
2. Identify unusual or outlying points
3. Compare the shape of two independent datasets
4. Identify relationships between two variables in a dataset. - 10What are simple scatterplots?x-y plots
- 11What are scatterplot matrices?Several simple scatterplots put together to show multiple variables.
- 12WC
- 13WAllow the shape of one set of data to be easily seen compared to the continuous data set.
- 14What is another name for a histogram?Frequency histogram
- 15What might be used to compare two sets of data side by side?Dot plot
- 16What might be done on a dot plot, with a categorical variable on the x axis, to allow all points to be seen?Jittering, slight sideways (x-axis) movement
- 17What is the median?The middle piece of data after the dataset has been ordered.
Odd number of data: always middle point
Even number of data: the average of the two middle data points - 18What are 2 measures of spread?1. Range
2. Interquartile range - 19What is range?The highest data point take the lowest data point
misleading if outliers - 20What is the inter-quartile range?The range covered by the middle half of the data
- 21What is another name for the mean?X-bar
- 22How do you calculate the mean?Sum of values / number of values added
- 23What is the mean?The value that has the smallest sum of the distances between itself and the data points.
- 24What can be used to prevent the mean being affected by outliers?Truncated mean. Removing a predetermined number of points from each end of the list before calculating.
(has to be declared that this has been used) - 25When can you use a bar chart as a way of displaying data?- Discrete or categorical data.
- Look at a single dataset or to compare frequencies - 26What does a box and whisker plot display?Median
Quartiles (upper range, upper quartile, lower quartile, lower range) - 27What is the mode of a dataset?Most common value
- 28What can the 'average' of a dataset represent?Either median, mean or mode value
- 29What is the standard deviation?A measure of variation which gives an indication of the average spread of the data about the mean.
Approximately the average of the squares of the distance between all the points and the mean. - 30When is the standard deviation a useful tool for calculating probabilities from the data?Where data are approximately 'normally distributed'
- 31What are the set of normal distributions represented by?F
- 32What 2 numbers define the y-value (frequency) of a normal distribution curve?1. The mean
2. The standard deviation (or variance which is standard deviation squared) - 33What do 67% of a datasets observations fall within?+ or - 1 standard deviation of the mean.
- 34What do 95% of a datasets observations fall within?+ or - 2 standard deviations of the mean
- 35What can be done to continuous data that isn't normally distributed to approximate normality?Transformed
- 36What is used in biological data to transform data to a normal distribution?Data log transformation
- 37What type of transformation is acceptable to generate a normally distributed data set?Any Reversible
- 38If you have used a log transformation, how do you then work out the mean and standard deviation?Use the log of the data
- 39Why might you transform data when trying to gain an overall result?Some variable may have a greater impact due to a larger variation in values so transforming data normalises it to reduce the weight gained by one variable.
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- Beschreibung
- BVSc 2. Animal management 2 (Statistics) Karteikarten am Statistics 1, erstellt von Rachael Jones am 12/10/2016.
- Erstellt von
- Rachael Jones
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