Below are some suggestions on how to define your data topic and also a few strategies to help you get started with finding datasets.
As you begin your search for data, it is important to define your topic as clearly as possible. You might also need to be prepared to change your topic depending on available data sources. Please keep in mind that data is not available for all possible topics. Sometimes data is proprietary, sometimes it has not been collected, sometimes it does not exist in a format that is convenient to researchers, etc. There may be situations where you need to adjust your topic and try searching for other types of data.
As you define your topic, you might find it helpful to check the Articles & Journals page of this guide to look for articles or research papers that will help you become better acquainted with your subject.
Examples of topics:
I need annual Consumer Price Index data for the United States, Canada and Spain for the last 20 years.
What is the average income level in the United States by ethnicity for the last 10 years?
What are the crime rates for gun-related offenses by state for the past 10 years?
What are the educational attainment rates in Massachusetts by race for the past 20 years?
Search Strategy #1: Literature Search
You can search for literature on your topic using the Articles & Journals page of this guide to find relevant articles. A literature search is important since it can give you an idea of what others have researched. You could then try to either replicate the author's work or use it as a basis for your own research. A very important reason for a literature search is to find out the sources of their data. Since there are a lot of possible data sources, you might have to be creative with your keyword search to locate the right source(s). Using data sources mentioned in journal papers or books can often save you a lot of time.
Search Strategy #2: Identify Potential Producers
Think about who might collect and/or publish the type of data that you are hoping to work with. If you have an idea of who might have the data that you need, try visiting the organization's website to see if any data is freely available.
If the data is produced by a government source, you might try checking the Government Data Sources page of this guide. If the data is from a global organization, such as World Bank, you might try checking the Global Organizations Data Sources page of this guide. Another approach might be to try searching for the data producer by organization name in the Statistical Abstract of the United States or Statistical Abstracts of the World.
Search Strategy #3: Search in a Data Repository
This may not be the most effective search strategy, but it can be very helpful to search a data repository that collects within the subject area that you are researching. For business or economic data, the repositories listed on our Social Science Data Repositories page might be a good place to search.
Search Strategy #4: Cast a Wide Net
If you are not sure where else to look for data, you might try using Google Dataset Search. Although it is still in Beta, it can be an effective way to locate datasets hosted in thousands of repositories on the Web. The sources listed on the Free Publicly Available Data page might also be a good place to search.