Accessing Data
Browsing data holdings
NZSSDS’s data and metadata holdings are presented through Nesstar, with a WebView interface of surveys categorised into fields within the social sciences in a hierarchical structure. Nesstar stores detailed metadata next to actual survey data sets; the metadata can be accessed freely online, along with simple variable summaries.
Permissions
If you want to perform cross-tabulations, correlations and regressions, or to view data graphically online, you will need to register with NZSSDS. You will be prompted to log in when you try to perform analyses.
If you want to download data sets, you will in most cases need to fill out, sign and return a User Undertaking Form, after which you will be granted permission to download data from the specified survey(s). Files for download are converted on the fly, with a number of supported formats, including simple CSV as well as formats for SPSS, SAS, Stata, Statistica and more.
Some data sets will be classified as 'restricted' and require more forms to be filled out; no such data sets exist in the NZSSDS holdings at present, however.
Nesstar
Navigation of Nesstar WebView is by way of a tree structure, as shown below. Clicking the little icons to the left takes you deeper into the structure, while clicking the headings loads the specific content. Within the analysis interfaces, left-clicking on a variable name provides options for including that variable in the crosstabulation/correlation/regression, as shown below. The toolbar icons to the top of the WebView interface provide further options for analysis and download; these are described briefly below.
From left to right, the toolbar icons are used as follows:
- Table: return to table view from a graphical or other analysis.
- Graph: select between different graph layouts the 'tabulation' interface. Depending on the types of variables in your table, there may be bar charts, box and whisker plots, mean deviance plots, confidence interval plots and/or pie charts available. This button becomes 'regression chart' when in the analysis interface - this shows the regression equation and percentage of variance explained.
- Time series graph: this option is only available with at least one variable representing time. It produces a line graph of changes over time. This button becomes 'scatterplot' when in the analysis interface.
- Map: this option is only available for data sets that were uploaded with an external link to a map.
- Clear: this empties the current analysis of variables, allowing you to quickly start on a new crosstabulation, for example.
- Weight: this gives you more information about any weighting variables that are defined in a data set, and allows you to define another variable as a weighting variable for analysis.
- Subset: this allows you to subset or filter the contents of a data set for online analysis, based on defined variable properties.
- Compute: this offers a number of different calculations that you can use to define new variables, as well as the ability to recode existing variables.
- Download: this is the button to press for downloading held data sets. It immediately prompts you to log in, and you may not have permission to download some data sets (see above for more details).
- Export table to spreadsheet: this downloads a plain text spreadsheet compatible with Microsoft Excel, of the current analysis. Depending on your browser settings, you may need to confirm that you want to allow this download.
- Export pdf: this opens the current analysis as a portable document format file that you can then save locally.
- Print preview: this shows you how a print-out of the current analysis would look, and then prompts you for printing preferences.
- Create bookmark: this allows you to create bookmarks so that you can return to a particular analysis of interest within the Nesstar interface. 'Bookmarks' appears below the metadata and variable information in the left pane. 'Browser bookmarks' are stored on your own machine; 'Server bookmarks' are saved to the Nesstar server and thus require higher permission levels, and may not be available.
- Help: easily the most useful toolbar button, this links to Nesstar's own help interface, which offers significantly more detail than this list, on every facet of the available online analyses. Highly recommended.