Expert search

Using Expert Search

The expert search service provides access to the full range of functionality provided by Nokia Developer semantic web enabled search solution, as well as complete access to the full variety of content available throughout Developer Nokia website.

The expert search service isn't for everyone. It is intended for Nokia Developer "power users" who require the extra expressive query power provided by the service. For those who are willing to learn how to use the service effectively there will be tangible benefits. But if you do plan to use this service, please understand that there will be added complexity involved.

Note: The expert search service is an excellent way to define custom syndication feeds.

Unlike the basic search service, the expert search service defaults initially to an exact match search, based on default options pre-selected in the form. You can modify this default behaviour to achieve a best match search, possibly with a mix of both mandatory and optional search criteria.

The expert search function providses full access to every metadata property relevant to search as defined in the Nokia Developer ontologies (categories of content). When using expert search, the query form initially presents drop-down options for the four most commonly used properties (type, topic, title, and description), and it also provides a link to add more metadata criteria to the query, if needed. [See Figure 1]

Figure 1:  

The most important of the four properties listed above is "type". When conducting an expert search, it is recommended that you consider specifying the particular type of resource that you are searching for first, because any additional criteria that you choose will be adjusted to include only those which are relevant for the specified resource type(s). For example, if you specify the type to be a "Mobile Device", additional criteria will include properties specific to mobile devices, but not documents. This is covered in more detail below.

Expert search results may be ordered by score (best match), date, or title. By default these search results are ordered by score, which for exact match searches (where all criteria are mandatory) results in sorting by date. This is because resources with an equivalent score are sub-ordered by date when sorting by score, and with an exact match search all targets in the search results will have an equivalent score. However, if any optional criteria are introduced to the query, the search then becomes a best match search, and the default ordering will reflect how closely targets match the optional criteria.

Please note that both Archived and non-English resources are excluded from expert search by default. To include these resources, simply deselect the corresponding checkbox at the top of the search form. These exclusions can also be defined for any query using the appropriate properties, values, and comparison operators. The default checkboxes are provided for your convenience.

Keyword Search Criteria
All metadata criteria options presented in the search form are derived directly from the Nokia Developer ontologies, and updates to the ontologies are reflected in the search form automatically.

Metadata Search Criteria
All metadata criteria options presented in the search form are derived directly from the Nokia Developer ontologies, and updates to the ontologies are reflected in the search form automatically.

The expert search function is designed so that the metadata search criteria defined in the search form can be read as normal English (e.g., "type must be equal to Document"; "topic should be equal to Java"; "screen width must be greater than or equal to 300 pixels").

Metadata Criteria Form Widgets
Each metadata criteria are specified in a distinct form widget (drop-down options) which can have at most one value defined (each metadata search criteria correspond to a single query facet). If more than one value for a given search query is needed, a separate widget must be defined for each value using the “Add criteria…” link for any additional values to be included in the search query.

As noted above when adding new metadata criteria, the list of properties presented varies depending on the specified resource type(s), such that only those properties which are relevant for the specified type(s) are shown. Therefore, as an initial step, you should define any applicable resource types that you are searching for first. If no resource type is specified, a general set of properties relevant to all resources is presented.

Each metadata search criteria can be specified as either mandatory (the default) via the "must" pull-down menu option, or as optional if you use the "should" option instead. If you specify "should" for a given criteria and all other criteria match equally, then those resources which match the optional criteria will score higher than those that do not. At the same time, failing to match those criteria will not exclude the resource from the search results, if it matches other criteria.

Optionally, you can remove metadata criteria from your search query by clicking on the 'X' to the right of the specified form widget.

Property Value Comparisons
The set of value comparisons for each criteria presented in the pull-down will vary depending on the value type.

Properties with controlled value sets (pull down menus where you select one of the available options) will have available the following comparisons:

• be equal to [default]
• not be equal to
• be defined
• not be defined

If either the "be defined" or "not be defined" option is selected, no value can be input.

Properties with text-based values can use the following comparisons:

• contain [default]
• not contain
• be equal to
• not be equal to
• sort before
• not sort before
• sort after
• not sort after
• be defined
• not be defined

Properties with numeric values can use the following comparisons:

• be equal to [default]
• not be equal to
• be defined
• not be defined
• be greater than
• not be greater than
• be less than
• not be less than
• be greater or equal to
• not be greater or equal to
• be less than or equal to
• not be less than or equal to

Note that some of the comparison options for numeric values are synonymous (e.g. "less than or equal to" is the same as "not greater than"). These functionally equivalent alternatives are provided so that the expert search function accommodates your current thinking as you specify your query, and does not require that you rethink your desired criteria to fit a narrower set of options.

Property Value Input
Properties with controlled value sets will have a pull-down selection menu presenting the controlled values defined in the ontologies. If the controlled value set is organised as a taxonomy, the list of values will be hierarchically indented.

Properties taking data-typed values will have a text input box; and user input values will be validated according to the specified data type (e.g., entering 'Bluetooth' in a value field for a property requiring an integer value will be rejected).

Furthermore, if the property value corresponds to a unit of measure, there will be a pull-down that you can use to select a particular magnitude applicable to the input value (e.g. bytes, kilobytes, megabytes, etc.). Note that all values expressed using a unit of measure are normalised internally using the smallest unit of measure, so that no matter which magnitude is used in the search form, the comparisons will be valid from one search query to the next.

How are Expert Search results displayed?
Expert search results are presented in a similar fashion to basic search results. A new web page will be displayed, and your search results will be shown in a paginated order, with numbered links at the bottom of each results page, allowing you to quickly navigate to subsequent search results pages. Both a summary of the search criteria and the search results are presented on the results page. [See Figure 2 below.]

Additionally, there is a feed subscription link icon () at the top of the results page that you can use to save your current search results as a feed for future use. Finally, there is a text-based link (labeled "refine your query") that you can use to return to the expert search form and further refine the parameters of your search query, or you can begin an entirely new search.

Figure 2: