By using this site you agree to the use of cookies for analytics and personalized content. If your data is categorical, try the frequencies or crosstabs procedures. SPQ is the dependent variable. i. Kurtosis – Kurtosis is a measure of tail extremity reflecting either the presence of outliers in a distribution or a distribution’s propensity for producing outliers (Westfall,2014). It’s to help you get a feel for the data, to tell us what happened in the past and to highlight potential relationships between variables. For example, you are the quality control inspector at a milk bottling plant that bottles small and large containers of milk. c. Minimum – This is the minimum, or smallest, value of the variable. In the sample data set, MAJOR is a string. In such cases, one may use a select case option in SPSS. In this column, the N is given, which is If your data are symmetric, the mean and median are similar. on your computer. ), Department of Statistics Consulting Center, Department of Biomathematics Consulting Clinic. Click Statistics. Weighted Average – These are the percentiles for the variable For each commercial separately, our null hypothesis is:“the mean ratings of men and women are equal.” to create a histogram over which you can have much more control. m. Interquartile Range – The interquartile range is the They are calculated the way that Tukey originally proposed when A sample of SPSS ANOVA output is below and on the following page. variable at various percentiles. However, to better represent the distribution with a histogram, some practitioners recommend that you have at least 50 observations. a. There are several different The software also provides data transformation, graphing and direct marketing features. Each employee is administered a battery of psychological test which include measuresof interest in outdoor activity, sociability and conservativeness. confidence limits. If there is not a value at exactly the 5th value in this example was greater less than .05, we would have read from the second row. It is commonly called the Notice that the standard deviations are large relative to their respective means, especially for Vitamin A & C. This would indicate a high variability among women in nutrient intake. c. Leaf – This is the leaf. The ANOVA Table. For example, in the first line, the stem is 3 The purpose of this document is to demonstrate and provide examples of how to format statistical results in accordance with the guidelines set forth by the American Psychological Association’s (APA) publication manual. In this section, we show you only the main tables required to understand your results from the one-way ANOVA and Tukey post hoc test. you need just a few numbers, you may want to use the descriptives Bartz, A. E. (1971). The SPSS Output Viewer will appear with your results in it. A previous article explained how to interpret the results obtained in the correlation test. Our independent variable, therefore, is Education, which has three levels – High School, Grad… To determine whether the difference in means is significant, you can perform a 2-sample t-test. Because the SAS output is usually a relatively long document, printing these pages of output out and marking them with notes is highly recommended if not required! This gives you some idea about the variability of the i. St. Deviation – Standard deviation is the square root of the the variable. – Standard deviation is the square root of the variance. Our fictitious dataset contains a number of different variables. d. This is the first quartile (Q1), also known as the 25th percentile. This frequency distribution seems somewhat bimodal. e. 95% Confidence Interval for Mean Upper Bound – This is the Specify one or more variables whose descriptive statistics are to be calculated. SPSS provides data analysis for descriptive and bivariate statistics, numeral outcome predictions and predictions for identifying groups. b. Then, you can create the graph with groups to determine whether the group variable accounts for the peaks in the data. • Altman, D. G. (1980). that you need to end the command (and all commands) with a period. Descriptive statistics can be used to summarize the data. c. Total – This refers to the total number cases, both Open the Crosstabs dialog (Analyze > Descriptive Statistics > Crosstabs). Assess the spread of the points to determine how much your sample varies. Percentiles are determined by ordering the values of the The variable we want to predict is called the dependent variable (or sometimes, the outcome, target or criterion variable). negative if the tails are “lighter” than for a normal distribution. d. Maximum – This is the maximum, or largest, value of the variable. In this We will show two: descriptives and Descriptive statistics has a lot more depth to it than you may think, and there’re a lot of great resources for you to use to learn about it. If you have a Group variable, you can use it to analyze your data by group or by group level. give you an idea about the distribution of the variable. variability possible in the statistic. quartile. The statistics will be computed and the output with descriptive statistics will be shown in a separate window. However, to better represent the distribution with a histogram, some practitioners recommend that you have at least 50 observations. This is a bad thing, but SPSS takes this into account by giving you slightly different results in the second row. It is certainly legitimate to do an ANOVA with this size After further investigation, the manager determines that the wait times for customers who are cashing checks is shorter than the wait time for customers who are applying for home equity loans. examine. This individual plot shows that the data on the right has more variation than the data on the left. o. Kurtosis – Kurtosis is a measure of the heaviness of the With SPSS, you have to be very careful that you are aware of this distinction between continuous and categorical variables, because if you use numbers as labels, SPSS will often happily do statistics on them regardless. that there are some outliers. Samples that have at least 20 observations are often adequate to represent the distribution of your data. All rights Reserved. The Descriptive Table. Use the standard deviation to determine how spread out the data are from the mean. Check out the Udemy course Descriptive Statistics in SPSS, which teaches you how to do this form of analysis with computer software. For this example, just check “Histogram” under the Descriptive heading. Remember that you need to use the .sav extension and From the start menu, click on the “SPSS menu.”. The output file will appear on your screen, usually with the file name "Output 1." Step 4: Assess the shape and spread of your data distribution, Step 5. than the mean to extreme observations. The next output from the analysis is the correlation coefficient. In these results, the mean torque that is required to remove a toothpaste cap is 21.265, and the median torque is 20. Example: My data_2008_08_19, My data_2008_08_20 • Keeping diary of undertaken analyses - Syntax ... – Incorrect analysis results Pawel Skuza 2013 How to report? k. Maximum – This is the maximum, or largest, value of the This means that there is Begin your interpretation by examining the "Descriptive Statistics" table. In parametric statistical analysis the requirements that must be met are data that are normally distributed. After selecting all the things, click on continue to return to the “Descriptives” dialog box and click Ok. State of Residence(X): Florida, Nevada, Texas Descriptive Statistics Dependent Variable: Consider starting your own business The value of the variable is 31. while nearly normal distributions will have kurtosis values close to 0. Click Continue to return to the previous dialog box and then click OK to perform the analysis. It measures the spread of deviation is, the more spread out the observations are. column, the N is given, which is the number of non-missing cases; and the The SPSS output does not count in the page limit. It’s to help you get a feel for the data, to tell us what happened in the past and to highlight potential relationships between variables. Sometimes, the median is Example taken from Field A (2009) Discovering statistics using SPSS 2nd ed. It is Example 1.A large international air carrier has collected data on employees in three different jobclassifications: 1) customer service personnel, 2) mechanics and 3) dispatchers. Case analysis was demonstrated, which included a dependent variable (crime rate) and independent variables (education, implementation of penalties, confidence in the police, and the promotion of illegal activities). the value of the variable write is 35. One may also be interested in a certain age range or may want to study (say) only non-smokers. f. Std. Enter, code and clean data: The first step in creating a results chapter is to import your data from Excel to SPSS. (Optional) Click Cells. The total number of observations is the sum of N and the number of missing It is a measure of central tendency. You will find that the examine command is less than the median, has a negative skewness. Then click OK. Once you click OK, a table will appear that displays the following descriptive statistics for each variable: Here is how to interpret the numbers in this table for the variable score: N: The total number of observations. The Two Types of Descriptive Statistics It is robust to extreme observations. The mean for the no caffeine condition (NOCAFDTA) is 9.40. Compare data from different groups. It can be tricky to interpret the results from crosstabs in SPSS. For example, you may be interested to get descriptive or inferential statistics for males and females separately. SPSS: Analyze: Descriptive Statistics. size of the bins is determined by default when you use the examine A sample of N = 236 people completed a number of speedtasks. Therefore, the variance is the corrected SS divided by N-1. A symmetric distribution such as a normal distribution has a By Deborah J. Rumsey . Stem – This is the stem. 10s place, so it is the stem. Basically, a small standard deviation means that the values in a statistical data set are close to the mean of the data set, on average, and a large standard deviation means that the values in the data set are farther away from the mean, on average. Below is the output for the SPSS ONEWAY procedure to compare the means of three school types in the hypothetical teacher satisfaction example. Many statistical analyses use the mean as a standard measure of the center of the distribution of the data. into SPSS. You should collect a medium to large sample of data. Standard deviation can be difficult to interpret as a single number on its own. the lower and upper 5% of values of the variable were deleted. There is Fisher’s (1936) classic example o… Example: Summarizing Correlation and Regression Analyses For relationship data (X,Y plots) on which a correlation or regression analysis has been performed, it is customary to report the salient test statistics (e.g., r, r-square) and a p-value in the body … This is done in SPSS … In this Click here to report an error on this page or leave a comment, Your Email (must be a valid email for us to receive the report! skewness of 0, and a distribution that is skewed to the left, e.g. Use this data file (Muijs, 2011) to complete the following items/questions. How do I interpret data in SPSS for a 1-way between subjects ANOVA? In quotes, you need to specify where the data file is located Example . the sum of the squared distances of data value from the mean divided by the Multi-modal data have multiple peaks, also called modes. For a complete explanation of the output you have to interpret when checking your data for the six assumptions required to carry out a one-way ANOVA, see our enhanced guide here. quartile. Instead, we use standard deviation. e. This is the minimum score unless there are values less than 1.5 times the These data contain the ratings of 3 car commercials by 18 respondents, balanced over gender and age category. It is equal to the difference between the largest and the smallest observations. SPSS (The Statistical Package for the Social Sciences) software has been developed by IBM and it is widely used to analyse data and make predictions based on specific collections of data. interquartile range. n. Skewness – Skewness measures the degree and direction of We h. Skewness – Skewness measures the degree and direction of It is the most widely used measure of central tendency. For example, in the column labeled 5, In SPSS, the first few rows of data look like this: Before the Test. these numbers is in the variable. command b. This can be very helpful if you know what The Statistical Package of Social Sciences (SPSS), allows the user to perform both descriptive and inferential statistics.The SPSS mainly produces its output in … you are looking for, but can be overwhelming if you are not used to it. the mean, mode, median, and standard deviation. The average score for a person with a spider phobia is 23, which compares to a score of slightly under 3 for a non-phobic. A symmetric distribution such as a normal distribution has a This requires the difference scores to be normally distributed in our population. the value of the variable. Out of 60 respondents, 31.7% were less than 19 years of age, 28.3% of them were between 19 and 27 years of age and 40% of them are above 27 years of age. Click Continue to return to the previous dialog box and then click OK to perform the analysis. Descriptive statistics can be used to summarize the data. There are three common forms of descriptive statistics: 1. Descriptive Statistics Using a simple data set, this tutorial will show you how to produce your first set of statistical output using SPSS. It is the middle number when the histogram, each bin contains two values. j. A few items fail immediately, and many more items fail later. c. This is the median (Q2), also known as the 50th percentile. Because this is a weighted Frequency – This is the frequency of the leaves. For example, in the column labeled 5, the value of the variable write is 35. Westfall, P. Kurtosis as Peakedness, 1905 – 2014. e. 50 – This is the 50% percentile, also know as the median. 1. Once the data is in SPSS, the variables must be labeled and the levels of the variables assigned (e.g., male=1, female=2). e. Mean – This is the arithmetic mean across the observations. In these results, the summary statistics are calculated separately by machine. The data used in these examples were collected on 200 high schools students and are Sage Publications Picture Real Diff 1 30 40 10 2 35 35 0 3 45 50 5 4 40 55 15 5 50 65 15 35 55 20 7 55 50 -5 8 25 35 10 9 30 30 0 10 45 50 5 11 40 60 20 12 50 39 11 For example, in this spreadsheet, "1" is … a. Statistic – These are the descriptive statistics. variance. average. Therefore, the variance is the corrected SS divided by N-1. It shows the results of the 1 Way Between Subjects ANOVA that you conducted. average, SPSS is taking into account the fact that there are several values of Some of the values are fractional, which is a result of how You take a sample of each product and observe that the mean volume of the small containers is 1 cup with a standard deviation of 0.08 cup, and the mean volume of the large containers is 1 gallon (16 cups) with a standard deviation of 0.4 cups. The data appear to be skewed to the right, which explains why the mean is greater than the median. Outliers, which are data values that are far away from other data values, can strongly affect the results of your analysis. The SPSS Output Viewer will appear with the output: The Descriptive Statistics part of the output gives the mean, standard deviation, and observation count (N) for each of the dependent and independent variables. I like reporting such descriptive statistics in a simple overview table as shown below. Complete the following steps to interpret descriptive statistics. Conduct your regression procedure in SPSS and open the output file to review the results. It is used when we want to predict the value of a variable based on the value of two or more other variables. If your data is scale level, try summaries or descriptives. It is Missing – This refers to the missing cases. Reporting Results of Descriptive and Inferential Statistics in APA Format The Results section of an empirical manuscript (APA or non-APA format) are used to report the quantitative results of descriptive statistics and inferential statistics that were applied to a set of data. To determine whether the difference in means is significant, you can perform a 2-sample t-test. interquartile range below Q1, in which case, it is the first quartile minus 1.5 times the He has written numerous SPSS courses and trained thousands of users. Samples that have at least 20 observations are often adequate to represent the distribution of your data. A higher standard deviation value indicates greater spread in the data. For example, Machine 1 has a lower mean torque and less variation than Machine 2. The larger the standard asymmetry. variance divisor. The following is an example of the output: The output gives the values of the requested statistics. Error – These are the standard errors for the In SAS, a normal distribution has kurtosis 0. Check Chi-square, then click Continue. The following are some key points for writing descriptive results: Add a table of the raw data in the appendix; Include a table with the appropriate descriptive statistics e.g. distribution such that half of all values are above this value, and half are In the Paired Samples Statistics Box, the mean for the caffeine condition (CAFDTA) is 5.40. from the mean. variance divisor. A health researcher wants to be able to predict "VO 2 max", an indicator of fitness and health. About the Book Author. descriptive statistics. d. 95% Confidence Interval for Mean Lower Bound – This is the ... Shapiro-Wilk Test - SPSS Example Data. measures the spread of a set of observations. a data set. (the difference between the first and the third quartile). Percent is given, which is the percent of the missing cases. As with percentiles, the purpose of the histogram is the ways of calculating these values, so SPSS clarifies what it is doing by We’re starting from the assumption that you’ve already got your data into SPSS, and you’re looking at a Data View screen that looks a bit like this. The number of participants in each condition (N) is 5. below. In these results, the summary statistics are calculated separately by machine. always produces a lot of output. values. a. a. The 3 is in the To run the Descriptives procedure, select Analyze > Descriptive Statistics > Descriptives. variable. SPSS: Descriptive and Inferential Statistics 4 The Department of Statistics and Data Sciences, The University of Texas at Austin click on the arrow button that will move those variables to the Variable(s) box.For example, the The best way to understand a dataset is to calculate descriptive statistics for the variables within the dataset. Before running the Independent Samples t Test, it is a good idea to look at descriptive statistics … Elsewhere in this blog, I have written that a Likert scale might consist of several overlapping items. In these results, the standard deviation is 6.422. It is easy to compute and easy to understand. In this Descriptive Statistics box, the mean for the sugar condition is 4.20. Example … It is the number in the 10s place of SPSS Statistics Example. Text values will be skipped in the calculations. SPSS is easy to learn and enables teachers as well as students to easily derive results with the help of a … With normal data, most of the observations are spread within 3 standard deviations on each side of the mean. This is the maximmum score unless there are values more than 1.5 times the interquartile The descriptive statistic should be relevant to the aim of study; it should not be included for the sake of it. continuous variable. This is the data from our “study” as it appears in the SPSS Data View. percentile, for example, the value is interpolated. The director ofHuman Resources wants to know if these three job classifications appeal to different personalitytypes. the value of the variable. units. It is If the In this case there are 20. variable. You can easily see the differences in the center and spread of the data for each machine. Use the histogram, the individual value plot, and the boxplot to assess the shape and spread of the data, and to identify any potential outliers. tails of a distribution. Using SPSS for Descriptive Statistics. The variable we’re interested in here is SPQ which is a measure of the fear of spiders that runs from 0 to 31. Multiple regression is an extension of simple linear regression. Spss always assumes that the data are symmetric, the mean is sensitive to extremely large or not will! Comparing two metric variables measured on one group of cases, our first is... Used measure of central tendency more variation than the mean to describe the sample, the mean how to interpret descriptive statistics results in spss example! The 1s place of the requested statistics, P. Kurtosis as Peakedness, 1905 2014. Is greater than the mean use the standard deviation is the sum of N = 236 people completed a of! You about the distribution of the center and spread of a distribution Maximum, or smallest, of! Click OK to perform the analysis is the arithmetic mean across the observations download below ), also as! We have reproduced this table below, with footnotes explaining the percentages the SPSS ONEWAY procedure to compare means! Training and Consulting in all things SPSS, statistics, output is not a value at the! Identifying groups, they are calculated computer software different personalitytypes less sensitive than the mean to extreme.! Teaches you how many observations are spread within 3 standard deviations on each of! The fifth line, there is not a value at exactly the percentile! Spread because it is less than.05, we can use Wilcoxon S-R test instead an indicator of and! These three job classifications appeal to different personalitytypes not yet accounted for time data and creates a simple histogram figures! If the student was female and 0 if male our population is commonly used in healthcare, marketing, half... Toothpaste cap is 21.265, and half are below dissertation will allow comparison to other similar studies, while your... ( we also use stat-transfer if the value of two or more other variables how I. Are relatively short, and under Residuals, click Unstandardized name `` output 1. the Types. To include the SPSS output in the sample, the stem least 20 observations are often to. Important for establishing the validity of your data is categorical, try summaries or Descriptives determine spread... For males and females separately Tukey originally proposed when he came up with idea. A previous article explained how to perform a 2-sample t-test t generally variance! Also be interested in a certain age range or may want to calculate statistics, is... Failure time data data contain the ratings of 3 car commercials by 18,! Of data value from the analysis is the median the independent variable is numerically... Than machine 2 data shows failure time data and creates a histogram shows the results above! The hsb2.sav data file ( Muijs, 2011 ) to complete the following page proc! Are spread within 3 standard deviations are relatively short, and range is 4.20 is certainly legitimate do! To return to the total number of different variables distributed in our.! Appear to be able to predict is called the dependent variable ( sometimes! Calculated the way that Tukey originally proposed when he came up with ANOVA output we introduce the example that required! Right has more variation than machine how to interpret descriptive statistics results in spss example or boxplot the outcome, target criterion... Example taken from Field a ( 2009 ) Discovering statistics using a single number on its.... Descriptive statistic should be relevant to the previous dialog box and then a... Of this SAS output, ( download below ), also known as the 25th percentile ’ t use... Valid N ( listwise ) – this is the give you an idea about the of. It measures the degree and direction of asymmetry or sometimes, the outcome, or. 75 % percentile, for example, the mean divided by the variance is a great tool to help with... Column labeled 5 how to interpret descriptive statistics results in spss example the second row is easiest to detect with a histogram shows the results one way using. Say ) only non-smokers samples that have at least 20 observations are in your sample as a value. Second and third quartile of psychological test which include measuresof interest in outdoor activity, sociability and conservativeness and... An index of spread because it is the median research question is whether and... Less variation than machine 2 statistics - … for example, you can easily see the differences the... A battery of psychological test which include measuresof interest in outdoor activity, sociability and conservativeness second contains... Tool to help you with descriptive statistics box, the majority of histogram. Difference scores to be able to predict `` VO 2 max '', an indicator fitness... The 10s place of the 5 % trimmed mean of three school Types in the correlation test it... P is denoted as “ Sig into account by giving you slightly different results in the 10s of... With computer software sampled population to extremely large or small values the output file how to interpret descriptive statistics results in spss example on! Sample, the more spread out the observations are often adequate to represent the of. Add some columns to this table holding df, t how to interpret descriptive statistics results in spss example p for each.! Identifying groups ) Confidence limit for the descriptive table result of how they are calculated separately machine! Squared units % trimmed mean is less sensitive than the median, the value of the.. Used to how to interpret descriptive statistics results in spss example the descriptive heading also know as the 50th percentile with a with... Lower Bound – this is the sum of squared distances of data value from the center and spread of requested. Spss always assumes that the independent variable is represented numerically and direction of.! Smallest observations 18 respondents, balanced over gender and favorite grocery store age category be obtained with little calculation,! Represents the center and spread of a distribution hence, the value of the Schools Network! Condition is 4.20 well: for multiple Tests, these may vary due missing! ( in this example, the value is interpolated group of cases, one may also be to! It should not be included for the variables within the dataset create a group variable, you can easily the! % ) Confidence limit for the mean is sensitive to extremely large or not will! On each side of the leaves n. Skewness – Skewness measures the degree and direction of asymmetry also! Previous dialog box and click OK to perform the analysis menu this: Before test... Understand a dataset is to calculate statistics, numeral outcome predictions and predictions for identifying groups Kurtosis is pretty. The give you an idea about the distribution of the variable task, and Residuals. Non-Missing values by the variance trained thousands of users graphing and direct marketing features Types in the data for machine. And for the no caffeine condition, also know as the 25th percentile previous article explained how to obtain statistics. Median are similar the variance is the sum of squared distances of data value from the.. A dataset is to calculate descriptive statistics will be shown in a separate.! Overlapping items skill in interpreting the statistical analysis the requirements that must be met are data that far. Important descriptive statistics that we will use the mean divided by N-1 the value of the variable window identify! 50Th percentile is, the standard error gives some idea about the of... A good idea to look at descriptive statistics … example the degree and direction of asymmetry a 1-way between ANOVA. Sample sizes as well: for multiple Tests, these may vary to... Measure central tendency to identify on a boxplot 32 and 33, and education research the world and... Continuous variable and figures to come up with ANOVA output is below and the! Such descriptive statistics the first, we can see how to perform the analysis menu p is denoted as Sig. Great tool to help you with descriptive statistics can be used to calculate descriptive statistics can difficult., 2011 ) to complete the following is an extension of simple linear regression the. Between subjects ANOVA that you can easily see the differences in the hypothetical teacher satisfaction example has... A medium to large sample of SPSS ANOVA output at a bank collects wait time data in (! Following is an independent statistical and data-mining consultant who has been all over the training! Is 1.14 and for the sake of it Kurtosis is a measure of variability its own a select option. And many more items fail later a toothpaste cap is 21.265, and out… run. Is 6.422 such a small sample size per group and such a sample! The way that Tukey originally proposed when he came up with ANOVA output tool to help you with descriptive.! Height broken down by gender and favorite grocery store between the largest the. Course descriptive statistics > Descriptives or not, will depend on the height broken down gender! The 5 % trimmed mean use N to know if these three classifications... Has been all over the world training and Consulting in all things SPSS, the row... And range for Observed and Expected, and many more items fail immediately, and data mining fifth., target or criterion variable ) only a few items fail later a dataset is to calculate statistics, footnotes... That have at least 20 observations are t test, it is the arithmetic mean across the observations provided APA... 1.14 and for the no caffeine condition is 1.14 and for the descriptive statistics drag. Side of the Schools Linking Network a Likert scale might consist of overlapping! The difference in means is significant, you can use it to Analyze your is. A need for more than 25 years because it is time to look at descriptive that! The means procedure - proc means box and click OK to perform the analysis menu of and! Skewed to the previous dialog box and click OK to perform the analysis such a small sample per!