Are you getting too many results when you search an index? First, make sure that you are using the right keywords or subject terms. Then you can further screen out resources that don't meet your scholarly criteria by using advanced search features.
Not every index is the same. You'll see different interfaces and options depending on where you search, but there are some features that most indexes have in common.
Scholarly or Peer-Reviewed Journals: Look for a checkbox that will limit your search to return articles only from peer-reviewed journals.
Date: Does your topic neccissitate using only current resources (i.e., only those items written within the previous 5 years)? Specify a date range in your search criteria.
Language: Will you include resources written in languages other than English? Filter out foreign language materials or include only specific ones.
Article/Document Type: Use this to limit to different types of documents such as journal articles, reviews, editorials, book chapters, etc.
Taking the time to look over the advanced search features of an index can help you tailor your search to specific needs. Every index will have different features, often depending on the academic discipline that it caters to. For example, the PsychINFO index includes advanced search filters for research methodology and tests and measures.
Not every article index carries full-text of articles. Sometimes there is only an abstract (short summary) or a citation (joural title, article title, author, year of publication, etc). If you cannot find full-text of an article you want: