How to Write an Annotation and Annotated Bibliography or Reference List

Writing an Annotated Bibliography

Writing an Annotated Bibliography

At some point in time, your faculty may ask you to write an annotated bibliography or an annotated reference list.  This may happen in your undergraduate program, but it is more likely to be a requirement in your graduate program.  

This post will define terms, outline the difference between an annotated bib and an annotated reference list, discuss why these are useful tools for students and others, describe the types of annotations you can write depending on the purpose of your overview, and provide a how-to guide you can download for free! Click Here to Download my FREE How To Write an Annotation pdf!

First, What’s the Difference Between a Bibliography and a Reference List?

You may get an assignment that requires you to provide a bibliography or a reference list. Sometimes these terms may be used interchangeably, but they are not the same. 

A bibliography is a list of all sources the author used to develop their paper or research proposal, even if a source is not referred to in the document. So sources that are not cited within the narrative are still listed in the bibliography. This shows the breadth of the author’s research into a topic. Faculty may ask for all sources used to be cited in the bibliography (popular and professional articles, books, Internet sources, interviews) or restrict the list to selected sources (e.g., journal articles, textbooks, and Internet sources only). 

A reference list is a list of every source that was cited in your documentThe reference list contains ONLY sources cited in your document (i.e., in-text citations), NOT every source you may have read for background information. Any source you cite in the document MUST be in the reference list and every source cited in the reference list MUST be cited in the document! This type of list assumes that the author used a variety of sources for information, but only information or ideas that support the author’s points would have been credited by citing in the document and then only those in-text citations would be fully referenced in the reference list.  

If in writing your document you used a resource (Internet source, textbook, etc.) to give you background information about your topic, you would list the source in your bibliography. But unless you paraphrased or quoted information or ideas, which would need to be correctly cited, these sources would not go in a reference list. 

The purpose of both a bibliography and a reference list is to provide enough details about each source so that readers can find the sources you used for your research or cited in your paper.  All the components (author, title of source, journal/book title, edition, volume, issue, page numbers, etc.) need to be cited so your reader can find your sources! Follow the style formatting guidelines required by your instructor (e.g., APA, AMA, MLA). Bibliographies or reference lists may be found at the end of each of the document chapters (e.g., textbook chapters) or may be located at the end of the document in an appendix. 

What is an Annotation?

Let’s define “annotation.” An annotation is simply a summary of the source. It is a concise summary of an article (or chapter or book or other source) written in the reviewer’s own words. You may be asked to annotate your course readings (textbooks, novels, chapters, websites, etc.) by highlighting/underlining/circling key points and writing notes in the margins to help you summarize the main ideas.  Or you may write an annotation for a self-selected article to be shared with your classmates. Rereading your annotations can help you study and remember key points. 

An abstract may seem similar, but its purpose is to quickly present a simple descriptive summary of a work, usually a research study, conference topic, or other scientific work, to help the reader decide if the article will be helpful for their needs; not to convince the reader of its merits of the study itself. An abstract is frequently written by the author of the source as part of a manuscript for a journal article. 

When you provide a summary or annotation for a single source – so for a journal article you select, for example – that would be called an annotated reference or annotated article. I use this format a lot when I have students search the literature for relevant articles on a particular topic and then have them share one article with their classmates in a discussion board forum. I want students to get used to going to the literature for answers, so this type of assignment works to fulfill that purpose and teaches them to concisely summarize an article and evaluate its worth to their future practice. 

The purpose of an annotation is multifold: (a) to get a better understanding of your topic so that you can see the gaps in the science and pursue your own research and scholarship, (b) to “gain a good perspective on what is being said about your topic,” to “develop your own point of view,” and (c) (for an annotated bibliography) to assist other researchers and scholars make decisions about their own path (if your annotated bibliography is published!) (Online Writing Lab at Purdue University [OWL], 2013, para. 7-8).

Writing annotations also gives you practice in writing concisely, in learning to summarize and not re-write the article, and in helping you to think about how the source may used in your current or future practice. 

The process of writing annotations reveals whether you have correctly understood the piece you are writing about and it enables you to think about how you thought about developing your main ideas. This is a high level of critical thinking skill — I remember hearing Dr. Richard Paul present on critical thinking and defining it as “thinking about your thinking while you’re thinking!” (That quote occurred during a faculty development presentation to our nursing faculty. The Foundation for Critical Thinking was created by Dr. Paul and you can access the website here, if you are interested in learning more.)  

What is an Annotated Bibliography and Why is it Important?

Both an annotated bibliography and an annotated reference list are considered scholarly or academic writing.

An annotated bibliography is a list of all sources the author used to inform their work on a specific topic, using a specific formatting style (e.g., APA, AMA, MLA, etc.), where each source is followed by an annotation.  

An annotated reference list is a list of all sources cited in the document, using a specific formatting style (e.g., APA, AMA, MLA, etc.), where each source is followed by an annotation

This type of assignment is important because it gives the reader a greater understanding of each source, helps them decide if they want to read the source, if the sources are relevant for their purposes, and puts the topic, quickly, in perspective

Annotated “bibs” are especially useful for researchers and students doing a research proposal, thesis, dissertation, or capstone project: summarizing the work in a particular area helps you to become familiar with the topic by examining what’s been reported in the literature (provides a review of the literature) and, therefore, helps you see the gaps in the science that need to be answered. The annotations provide the author with a good reminder of what the particular sources provided relevant to the content of the paper. 

For readers [of the published document]: The annotation piece allows the reader to make a quick judgment about whether they would like to read the source for themselves and/or use a particular source for their own research. The citation then provides the reader the information they need to retrieve the desired source. 

Forms or Styles of Annotations

Annotations can be a simple summary of the source, a more detailed description of the source, an evaluation of the source, or a combination.

The length of an annotation will depend on the purpose of the annotation — if it is a simple summary or overview, then a few sentences to one paragraph may suffice. If the annotation is more of a deep analytical treatise, then one annotation may be many pages in length — this type of annotation is more common in a focused review paper and would NOT be used for an annotated bib/reference list. Suggested word counts are given, but realize they are estimates of length only. 

Indicative annotation: “This form of annotation defines the scope of the source, lists the significant topics included, and tells what the source is about” (The Writing Center, 2014, para. 1).  A brief book review is a good example.  “If someone asked what this article/book is about, what would you say?” (OWL, 2013, para. 3).

This type of annotation is typically one paragraph about 100-150 words in length.

This is a good style to use when writing about an opinion piece/editorial or a theoretical article.

  • Describe the purpose and scope of the article.
  • Describe the major points the author is trying to make.
  • Answer the question: What is the article about?

Informative annotation: “Simply put, this form of annotation is a summary of the source.  To write it, begin by writing the thesis; then develop it with the argument or hypothesis, list the proofs, and state the conclusion (The Writing Center, 2014, para. 4-5). 

This type of annotation is also known as a descriptive paragraph and is typically one paragraph about 100-150 words in length. 

This is a good style to use when writing about a research study.

  • Identify the purpose of the study. If not explicitly stated, you can derive the purpose from the research questions and/or hypotheses.
  • Summarize the research design briefly.
    • Include the type of research design, population studied, and sample size, and setting. You can briefly include all of this in one sentence. For example, “This descriptive study took place in rural Montana in seven counties and included 200 women, aged 20-35, diagnosed with post-partum depression.”
    • Identify the data collection tools and frequency of data collection.
    • Identify the type of data analysis used.
  • Summarize the key results.

Evaluative annotation: In this form of annotation you need to assess the source’s strengths and weaknesses.  You get to say why the source is interesting or helpful to you, or why it is not. In doing this you should list what kind of and how much information is given; in short, evaluate the source’s usefulness.  I usually have my students tell me how the information in the source could impact their current or future practice in 1-2 paragraphs.  See Step 5 below for what to include in an evaluative annotation. 

This type of annotation is also known as an Assessment or Reflective paragraph (OWL, 2013, para. 4-5). Again, this type of annotation could be short and sweet (e.g., 1-2 paragraphs, 100-150 words) or deep and analytical (e.g., pages). 

Combination annotation: “Most annotated bibliographies are of this type.  They contain one or two sentences summarizing or describing content and one or two sentences providing an evaluation” (The Writing Center, 2014, para. 8-9).

A combination annotation is usually brief, contains both the descriptive and evaluative content, and is roughly about 150 words.  Or you might be asked to do one paragraph that is descriptive followed by a separate paragraph that is evaluative. 

Want this information and additional tips by your side when you write?  Click Here to Download my FREE How To Write an Annotation pdf!

General Steps to Writing an Annotated Bibliography or Reference List

There are many resources from libraries (maybe from your own school!) that will guide you to writing an annotated bibliography. The following steps are general, but still will be helpful in how you think about structuring your annotation. 

Step 1: The number one step, ALWAYS, is to follow your instructor’s guidelines for the assignment!  Many faculty will take the time to tell you what they want to see in this assignment and how they want you to format it — so FOLLOW DIRECTIONS!

Step 2: Write the full citation of each source according to the style guidelines that you are required to use.  

Step 3:  Write a one-sentence summary of the article’s purpose. For example, “The purpose of this qualitative research study was to describe the lived experiences of families of patients undergoing transplants using a phenomenology as the research method.” OR “This article described the methods that faculty can use to engage students taking an online course.”

Follow this one-sentence summary with a summary of the article (Step 4).

Step 4: Summarize the author’s main points (for theoretical articles) or major findings (if a research study) in your own words.  Be sure to tell enough about the article so that the reader has an idea of what the article’s key points were. Follow the guidelines under the indicative or informative annotation, above, for what to include in each type of summary.

If you are just writing an indicative or informative annotation, you are done after Step 4. 

When writing just an evaluative annotation, substitute Step 5 for Step 4.

For a combination type of annotation, add Step 5 after Step 4.

Step 5: Evaluate the strengths and weaknesses of the source. Be critical. How credible is the author? How relevant is the source to your topic area? Critically reflect on the source and how it fits with what is known about your topic. 

You might also be asked to evaluate how the information can be used in your future work (research, thesis, etc.) or speculate how the information might be used in your clinical or professional practice or in nursing education, research, administration, or service. 

If the source is a research study, you might comment on how rigorous the research methodology was (reliability and validity of the instruments, sample representativeness, data collection methods, the limitations of the study, etc.) or how the study findings compare with others.

If the source is opinion, philosophical, or theoretical, you might evaluate or argue with the author’s premise or conclusions and/or evaluate the practicality of the argument to real life.

Keep the Following in Mind
  • The annotated bibliography or reference list starts on a new page, usually at the end of the paper. 
  • Leave one line in between the end of your reference and the beginning of the annotation. 
  • Indent the annotation under the reference citation. 
  • Some annotations may only be a few sentences or may have a word count to shoot for — 100-150 words is a common length for an annotation.
  • Write in full paragraphs of coherent, complete sentences. 
  • Use past tense.
  • NO quotes in an annotation!
  • Be objective when writing an indicative or informative annotation.
  • Be subjective when writing an evaluative annotation – but support your opinions and critiques with evidence!
  • Don’t rewrite the article! Don’t tell us the structure of the article (i.e., what the authors discussed first, second, third, and last.) Summarize! 
  • For those following APA format, realize that APA format requires a reference list, not a bibliography. Now, I’ll say it again, your instructor can alter APA format however they want! So if they tell you specifically to construct a bibliography, then that’s what you should do. Again, the difference is in documenting all your sources versus only those sources you’ve cited in the assignment. 
  • Oh, and since you are only talking about one source at a time, there is no need to have in-text citations in the annotation. We know which study you are summarizing! 
A Suggestion

I create a master bibliography list whenever I’m working on a manuscript, blog post, or research proposal so that I have all the sources I used or may use in one place. I start this master list while I’m doing my research and I add to it throughout my research.  If I use all the sources, great; if not, I still have them written down for future papers.

I make it a point to write down the full citation of a source in APA format with any URL right away, so I have all the components for a complete citation and so that I can find these sources again when I need them.

When I’m writing the draft of the paper, I start a reference list on the last page. I cut-and-paste the full citations of the sources I use from my master list when I cite them in the paper.  If I miss one, I’ll find it when I double-check my in-text citations against my reference list before submission. I can always retrieve the full citation of those references I missed from my master bib list.

I create my reference list first and then go back to add in the annotations after each reference. So the format of my final annotated reference list looks something like:

Author, A. A., & Author, B. B. (year). Title of article. Title of Journal, Volume(issue), xx-xy.      DOI: xxxxxxxxxxxxxxxxxxxxxxxxxx  Retrieved from http://source URL

    Annotation is indented and follows each citation according to the required elements.              Create your annotation. Indicative, informative, evaluative, or combined. 

Author, A. B., Author, B. C., & Author, D. E. full citation and repeat as above

Download my FREE How To Write an Annotation pdf now! 

What questions do you have about annotations or annotated bibs? Let me know in the comments!


Online Writing Lab at Purdue University. (2013, March 10). Annotated bibliographies. Retrieved from

Scribendi. (n.d.). How to write an annotated bibliography. Retrieved from

The Writing Center at The University of Wisconsin-Madison. (2014, August 29). What goes into the content of the annotations? Retrieved from