Homework Guide: Using Online Libraries and Databases

Moving beyond basic searches separates casual database users from power researchers. Advanced search strategies let you construct precise queries that return exactly what you need—no more, no less. These techniques seem technical at first, but once you understand them, you’ll wonder how you ever researched without them.

Boolean Operators Explained

Boolean operators are connecting words that tell databases how to combine your search terms. Named after mathematician George Boole, these operators form the foundation of database logic. Master these three words—AND, OR, NOT—and you’ll transform your research efficiency.

AND narrows your search by requiring all connected terms to appear in results. Think of it visually: when you search “climate change AND agriculture,” you’re finding only articles that discuss both concepts. The more AND operators you add, the fewer results you’ll get, but they’ll be more targeted.

Example: Searching “teenage depression AND social media AND Instagram” returns articles specifically examining Instagram’s impact on teenage depression. Remove one AND operator, and you’ll get thousands more results covering broader territory.

Here’s what confuses students: AND works opposite to how we use it in everyday language, where “and” usually means more. In databases, AND restricts. You’re creating an intersection—only retrieving articles where all your concepts overlap.

OR broadens your search by accepting any of the connected terms. This operator is perfect for synonyms and related concepts. Searching “teenagers OR adolescents OR youth” retrieves articles using any of these terms to describe the same population.

Use OR when:

• Different authors might use different terminology for the same concept
• You want comprehensive coverage of a topic
• You’re exploring a subject and don’t want to miss relevant articles due to terminology choices

Example: “(social media OR Facebook OR Instagram OR TikTok) AND mental health” captures articles regardless of which platform they specifically discuss.

NOT excludes terms from your results. While powerful, NOT can be dangerous because it removes results you can’t see, potentially excluding relevant articles that mention your excluded term only briefly.

Use NOT sparingly and strategically. If you’re researching renewable energy but keep getting articles about nuclear power, “renewable energy NOT nuclear” removes those results. But be careful—this also eliminates articles comparing renewable and nuclear energy, which might actually be useful for your research.

Practical Examples for Homework Research

Let’s see Boolean operators in action with a typical homework scenario. Your assignment: analyze the effectiveness of online learning during the pandemic.

Basic approach: online learning effectiveness pandemic

Better approach with AND: “online learning” AND effectiveness AND pandemic AND (college OR university)

Best approach combining operators: (“online learning” OR “distance education” OR “remote learning”) AND (effectiveness OR outcomes OR achievement) AND (COVID-19 OR pandemic) AND (college OR university OR “higher education”)

Notice how the sophisticated search uses parentheses to group related terms with OR, then connects those groups with AND. This captures articles regardless of which specific terminology authors chose.

Another example for a biology assignment on genetic disorders:

(“genetic disorder*” OR “hereditary disease*” OR “inherited condition*”) AND (diagnosis OR screening OR testing) NOT cancer

The asterisks here (discussed next) capture word variations, OR operators catch different terminology, AND combines your main concepts, and NOT eliminates the overwhelming cancer research that would otherwise dominate results.

Truncation and Wildcards

Databases are literal. They search for exactly what you type. Search “teach” and you won’t find articles about “teacher,” “teaching,” or “teachers”—unless you use truncation.

The asterisk (*) attaches to a word stem and retrieves all variations with different endings. Type “teach*” and you’ll get: teach, teacher, teachers, teaching, teachings, teachable.

More examples:

• child* = child, children, childhood, childish, childlike
• comput* = computer, computers, computing, computation, computational
• psycholog* = psychology, psychological, psychologist, psychologists

Be careful not to truncate too early in a word. Searching “comp*” would retrieve computer, competition, compensation, compound, complain, complete, and hundreds of other unrelated terms. The root doesn’t need to be a complete word, but shortening it too much produces too many irrelevant results.

Wildcards work similarly but for single character substitution. The question mark (?) typically replaces one character: “wom?n” finds both “woman” and “women.” This is less commonly needed than truncation but useful for variant spellings.

Some databases use different symbols for these functions, so check the help section. Most use asterisks for truncation, but wildcards might be ?, #, or $ depending on the platform.

Nesting with Parentheses

When combining multiple Boolean operators, databases can misinterpret your intent without proper grouping. Parentheses tell databases which operations to perform first—exactly like order of operations in mathematics.

Databases usually process AND as the primary operator first unless you use parentheses to specify otherwise. Without parentheses, searches can produce unexpected results.

Compare these searches:

Without parentheses: teenagers OR adolescents AND depression AND social media

The database reads this as: teenagers OR (adolescents AND depression AND social media) Result: Articles about teenagers in general, plus articles specifically about adolescent depression and social media—not what you wanted.

With parentheses: (teenagers OR adolescents) AND depression AND social media

The database now processes: (find teenagers or adolescents) AND (they must be discussed with depression) AND (they must be discussed with social media) Result: Articles about teenage/adolescent depression related to social media—exactly what you wanted.

Always use parentheses when combining OR with AND operators. Think of each concept as needing its own parentheses: (Concept 1 synonyms) AND (Concept 2 synonyms) AND (Concept 3 synonyms)

Complex example: (climate change OR global warming) AND (agriculture OR farming OR crops) AND (adaptation OR mitigation) AND (developing countr* OR “global south”)

This search systematically captures all terminology variations for each concept while keeping concepts distinct.

Proximity Operators

Proximity operators specify the distance between terms, telling databases how close together words should appear. These operators vary significantly between databases—always check the help documentation for specific syntax.

Common proximity operators include:

• NEAR/n (finds terms within n words of each other)
• WITH/n (similar to NEAR)
• ADJ/n (finds terms adjacent or within n words)

Example: “pollution NEAR/3 asthma” finds articles containing these terms within three words of each other—capturing phrases like “pollution-induced asthma,” “asthma caused by pollution,” or “pollution and asthma symptoms.”

Proximity searching helps when:

• Two concepts must be closely related, not just mentioned somewhere in the article
• You want to find specific relationships between terms
• Simple phrase searching is too restrictive

Building sophisticated search strings takes practice, but dramatically improves your results.

How do I combine multiple search techniques?

Start with your research question and break it into 2-4 main concepts. For each concept, list synonyms and related terms. Then construct your search systematically:

1. Group synonyms for each concept with OR, enclosed in parentheses
2. Connect concept groups with AND
3. Add truncation to catch word variations
4. Use NOT only if necessary to exclude irrelevant topics
5. Test your search and refine as needed

Example process for: “How does exercise affect academic performance in college students?”

Concepts identified:

• Exercise/physical activity
• Academic performance
• College students

Search construction: (exercise OR “physical activity” OR fitness OR sport*) AND (“academic performance” OR achievement OR grades OR GPA) AND (college OR university OR undergraduate*)

Run this search, review results, and adjust. Getting too much about professional athletes? Add NOT (professional OR elite). Too few results? Remove some terms or use fewer concepts. Search construction is iterative—expect to refine multiple times.