# Key concepts ## Questions The 3di has a bank of around 900 questions. During a typical assessment you will administer just a small subset of these questions. Questions are short and highly structured. There are several [question types](/using-the-software/question-types.md). All questions which contribute to the child's scores in the report have multiple choice or numeric answers. These are complemented by free-text answers which record qualitative information about the child's development for inclusion in the report, but you are free to skip these questions if you are interested only in the scoring tables. It is always an option to mark a question as not applicable, or to leave it unanswered. The 3di handles missing information in a robust way. You can [attach written notes](/using-the-software/conducting-an-interview.md#making-a-marginal-note-the-addnote-facility) of any length to a question, which will be included in your final report. ## Routes To perform a single assessment, for example the brief Autism Spectrum Disorder assessment, only a small subset of the question bank needs to be answered. We call a subset of questions a [Route](/using-the-software/routes.md). Normally you select a Route at the start of the assessment and follow it to completion, although the 3di allows you to switch between Routes at any time. While the [Interview Explorer](/using-the-software/conducting-an-interview.md#the-interview-explorer) shows every single available question, you will mainly use the [Route Explorer](/using-the-software/routes.md#opening-the-route-explorer), which displays just the questions on the currently selected route. ## Reports The output of a 3di assessment comes in the form of a [Word report](/using-the-software/reports.md) which can be generated at any time. Just as there are a range of questions and Routes, the full report contains many different components. If you fill in every single available question, the report will be fully populated. However in practice you will usually choose a shorter Route. You can then generate a report and delete any parts which are not relevant to your assessment. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.ixdx.org/readme/key-concepts.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.