Before you look for articles, you should determine what your topic is and identify keywords and phrases.
State your topic as a question: How does social presence theory affect online learning?
- identify the keywords/phrases: "social presence theory" "online learning"
- brainstorm for synonyms for the concepts:

Once you have identified keywords and phrases and synonyms, you are ready to formulate searches.
For example, for the topic How does social presence theory affect online learning? you might search for:
"social presence theory" AND "online learning"
If you don't find anything with that search, then you may want to think of adding some synonyms to your search:
("social presence theory" OR SPT) AND ("online education" OR elearning)
NOTE:
- The parentheses "( )" tell the database you will take the word social presence theory or the acronym SPT - this search will also include articles with both terms
- Never use acronyms such as SPT by itself, always put what it means in parentheses as in the example above