Link: Perplexity
What type of AI: Search engine and Generative AI Chatbot
User account: Immediate access is available on their homepage but you can also create a free account.
What it does: Generates responses to questions and prompts, and cites sources in the response. As a bonus, you don't have to create an account or log in to use the basic features.
Where it pulls information from: Perplexity AI is a search engine so it pulls sources from the internet (including Semantic Scholar) and summarizes them.
How to use it: Perplexity is a great tool for pre-research, or even for internet searching. Just remember to evaluate your sources!
The homepage allows you to start a search without creating an account. Just type a question into the search box to begin. You can use the dropdown for "focus" to identify your purpose and tailor the response.
I selected "Academic" to get sources I could use for a college paper.
The results page includes an answer to the question as well as a list of sources that was consulted.
Clicking on "view 2 more" sources brings up the full list of sources referenced in the response.
If one (or more) of these sources isn't relevant, you can check the box and remove it from the response.
Once you remove a source, Perplexity generates a new answer just using the remaining sources.
If you ask a follow up question, Perplexity will build on your previous question to answer, but it will provide you with new sources and a new summary of the response.
With a free account, you can use the Pro search 5 times every 4 hours (compared with the limit of 600 times per day with a paid account). Pro search provides additional steps between the question and answer that help narrow or better define a topic.
With Pro search, Perplexity provides additional sources to explore.