Search Help

Contents


Type of Search

There are two types of searching:

Searching VARIABLE-level information

A
collection is a group of datasets or studies. When you select one or more collections to search, and you indicate that you want to search for variable-level information (which is the default), the variable-level search screen appears.

These are the variable-level fields that are searched:

By default, the search will cover ALL of those fields, but you can select one specific field to search, by selecting it from the drop-down list. You can also select a specific combination of fields to search by using an advanced search technique to specify the field for each search term, as described in the advanced section below.

When the search results are displayed, you can see the full variable description for each variable found, by clicking on the 'View' button.


Searching STUDY-level information

A
collection is a group of datasets or studies. When you select one or more collections to search, and you indicate that you want to search for study-level information, the study-level search screen appears.

These are the study-level fields that are searched (if they exist for the study):

By default, the search will cover ALL of those fields, but you can select one specific field to search, by selecting it from the drop-down list. You can also select a specific combination of fields to search by using an advanced search technique to specify the field for each search term, as described in the advanced section below.

When the search results are displayed, you can see the full study description for a study by clicking on the 'View' button.


Collections

A collection is a group of datasets or studies. You must select one or more collections in which to carry out the search. You can select entire collections of datasets or individual datasets within one or more collections.

Selecting Entire Collections

Select an entire collection of datasets by clicking the empty box at the left of the collection name. Then all of the datasets in that collection will be searched.

Selecting Individual Datasets

To see the list of individual datasets within a collection, click on the box with the plus sign (+) at the left of the collection name. Or you can click the 'Expand All' button at the top of the list of collections. This will display all the datasets in all the available collections.

Select an individual dataset by clicking the empty box at the left of the dataset name.

After you have selected the collection(s) and dataset(s) you want to search, click on the button to 'Go to Next Step'.


Search Techniques

Most searches can produce good results by using a few
Basic Search Techniques.
For more complex situations see the section below on Advanced Search Techniques.


Basic Search Techniques


Search Terms -- What to search for in the text fields of a variable (or a study).


Finding Variables (or Studies) with ANY versus ALL of the Search Terms


Selecting Text Fields to search


Advanced Search Techniques



Field Syntax

By default, all fields in a variable (or a study) are searched. However, you can limit your search to specific fields -- variable name, variable label, question text, or category labels. If you want to search only one field, you can specify that field on the drop-down list of fields, as described above.

However, the special field syntax allows you to search for specific terms in specific fields by typing (in the search box) the field name followed by a colon (":") and then the term you are looking for in that field. (Note that you cannot put any spaces before or after the colon.) The short names of the fields for variablesare:

The short names of the fields for study descriptions are:

(The names of the fields are also shown in square brackets in the drop-down list for default fields to search.)

For example, if you want to find a variable with 'health' in the variable label and with 'insurance' in the question text, you could use the query:

label:health text:insurance

If you want to find variables with 'health' both in the label and in the question text you could use:

label:health text:health

Boolean Operators -- AND, OR, and NOT

The default operator is AND, which means that a variable must contain ALL of the search terms. The default can be changed to OR, which means that a variable only has to contain ANY of the search terms, by clicking the appropriate radio button under the search box, as described above.

If you want to specify combinations of operators, you must use explicit Boolean operators. The supported Boolean operators are: 'AND', 'OR', and 'NOT'. (Note that Boolean operators must be written in ALL CAPS, in order to distinguish them from the search terms.)

Those accustomed to Boolean searches can use the symbolic abbreviations for the operators. They are && (for AND), || (for OR), and ! (for NOT).

Using Parentheses with Complex Queries

If you form a query that contains complex Boolean logic, you should use parentheses to make your query unambiguous. For example, instead of using:

health OR insurance AND doctor

you should make your intention clear by supplying parentheses.

If a match must contain either 'health' OR 'insurance', but must also contain 'doctor', then you would use:

(health OR insurance) AND doctor

If a match must contain either 'health' OR both 'insurance' and 'doctor', then you would use:

health OR (insurance AND doctor)

If you do not use parentheses, you will still get a result, but the rules for operator precedence are complicated and hard to remember. So it is better just to use parentheses.