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How Do I Know a Genealogy Source is Correct?

How do you know a genealogy source is correct? You have to learn to evaluate your evidence. It's not as easy as "this is a good source." But it's not rocket science either!

image with text, quote is this source correct, unquote, learn to evaluate evidence

This post aims to explain the basic differences between asking "is this source right" and evaluating evidence. It's an introduction to evidence evaluation (also called evidence analysis, source evaluation, or source analysis).

Let's start with something really important. Checking a particular type of source is never "wrong." What makes the difference is what you do next.

Checking a particular type of source is never "wrong." What makes the difference is what you do next.

We always want to use the best available source in genealogy, but that doesn't mean skipping a source that isn't the best.

I see genealogists fall into traps at both ends of this issue. Some find a hint online, an online index entry, a database result, a free webpage, or a record from a book and stop there, never seeking out the original record. Other genealogists strive to do great genealogy but refuse to use whatever they don't consider the best source. This just makes your research harder.

Genealogists need to use whatever types of sources are available for their problem. Sometimes all you have is an index (sometimes, the records the index refers to are destroyed, and you literally are left with only the index). Sometimes you have various "derivatives" of a source, with some being easy to obtain, others being hard to obtain, and the original being really hard to obtain. You don't just NOT research that topic/person/source because you can't get the original. Use the derivatives and start with the easiest to get!

Evidence evaluation will help you know how much effort to put into getting that hard-to-obtain original or whether to continue to rely on a derivative. If your problem only has an index, evidence evaluation will help you identify other sources the index hints at.

Evidence evaluation is like your secret power to do genealogy no matter what situation you find yourself in. If you only use "the best" sources, you'll be perpetually getting stuck. Evidence evaluation not only frees you to use any source (appropriately) but will also help you shape what you do next, usually research, but possibly education.

I'll stop trying to convince you how great this skill is. Let's talk about how to do it.

How Do I Know a Genealogy Source is Correct?

I've told you the brief answer to this question, evidence evaluation. Let's break it down some more.

We don't ask if a source is right because a source can be right, wrong, and irrelevant. And one source can be all of those at the same time.

The easy-to-understand part of this is, a source can contain correct information and incorrect information. So there's the first key you must remember.

  • Sources contain information.

The next key piece is, we only care about information related to the question we're trying to answer. That means information not related to that question is irrelevant.

  • Information needs to relate to the question we're trying to answer.

Information we can use to help answer our question is defined in genealogy as "evidence." (So evidence has a specific meaning). Recognize that this is how you'd colloquially use the words evidence or clues. It does not mean the information has to be an answer.

  • Relevant information is "evidence."
  • Evidence doesn't' have to be an answer.

If you think about these key items, it should be obvious that we can't answer "is this source correct?" We also can't answer, "is this a good source?" Even if you determined a source contained all incorrect information, it is still possible to use it for clues.

There is such a thing as "negative evidence," as well, where not finding something provides evidence (this is an advanced use of evidence because it's very easy to do it wrong but highlights how even the lack of a source is possibly evidence, so you certainly don't want to label sources "good" or "bad"). "Good sources" can be irrelevant to our question or contain incorrect information. You don't want to paint all sources of any type as good or bad.

Evaluate your sources, instead.

We now have three key pieces to consider, and that's a good starting place. You can take these concepts further, so there is much more to learn about evidence evaluation than what I cover in this post.



Three keys to evidence evaluation

The three pieces I want to focus on are information, evidence, and questions. I don't really want to talk about "sources" in depth.

"Sources" are part of the evidence evaluation process, but since we're just dipping our toe in, I think that's actually a more advanced piece. Additionally, most people do get started with evidence evaluation because they want to know "is this source correct" or "is this a good source." By getting away from talking about sources, I think it helps get you over the bump of thinking that's the important question.

As a genealogist, you need to focus on evidence, not sources. Sources are sort of like the shipping box for the items you ordered. It has a crucial function but what you really care about is what's inside.

Yes, a damaged shipping box affects the items just as a source can affect evidence, but the damaged box doesn't mean your items are damaged, either. You don't just toss the entire box unopened because a corner got squashed in transit. Don't toss a source because it's "damaged." The evidence inside might be just what you need.

If you think about a shipping box and contents, this kinda highlights how evidence evaluation works. You open up the box and see what's inside. You saw the condition of the box (was it in bad shape, indicating possible issues with the contents?). Now you can see how the items are packed. Uh, oh! They didn't add any packing; your items might be damaged. So what do you do?

You check each item to see if it will still do what you need it to do.

That's what you do with evidence evaluation. Who cares about the box (once you get it). Will the information help with what you need. In other words, will the information help with the question you want answered?

The information might not answer the question but don't "send it back" if you can still use it!

That information is evidence.

You evaluate boxes shipped to your house, and this really is how evidence evaluation works in general. Some sources look great, undamaged box, appears well packed. You open it up and find they sent the wrong thing; the information isn't related to the question you need answered. You get another shipment, and the box looks just as good; you open it and see potential damage. You look closer; you don't just send it back without evaluating the state of the contents.

Looking Closer at Evidence

Evidence evaluation is how you consider the state of the box to help you decide how closely to examine the contents for damage. Issues with the container (the source) indicate careful evaluation of the contents (the evidence) is necessary. You need to be aware of potential problems with any source/information and then decide if the information you found has those issues.

You already do the reverse of this. If you believe the source is good, you don't check the information as carefully, just as when you receive an undamaged box, you don't minutely examine the items (if they appear fine) for damage. If only evidence evaluation was as obvious as checking your shipped items!

Using the shipped box example, evidence evaluation is like developing your eye into a magnifying glass. Genealogy is more complex than getting items in the mail. It doesn't make sense to microscopically examine a shipping box; a cursory examination is enough. In genealogy, we do want to look closer at our sources and then the information they contain. Evidence evaluation is how you will make your cursory glance far more detailed than it currently is. 

With practice, evidence evaluation becomes only slightly more difficult than evaluating items shipped to you. When you get started, it might seem extremely difficult. Just keep practicing. It's worth it!

You want to write down the results of your evidence evaluation. When you get pretty experienced, this will fit right into your notes or report. Until you do this naturally and easily, just write everything down when you evaluate your source. A lot of the point of evaluating evidence is for your future use of the evidence. While you're gaining experience, you can't be sure your future self will pick up on all the issues you see in the present. So write it down to make it easier for your future self. If you aren't keeping notes or writing reports to yourself, get out a piece of paper (real or digital) and just write down what you think, what you see, and any questions you have for yourself.

The Source Evaluation Workbook breaks the evaluation criteria into five easy-to-remember question categories which makes recording your evaluation simpler (this post only introduces you to four questions from three of the categories). The Workbook also includes two types of worksheets to help you learn to take source evaluation notes until you get enough experience to simply place your evaluation in your general genealogy notes.


Evidence Analysis Questions

Here are the fundamentals for evidence evaluation. Remember, this is just an introduction to this concept. Make sure to learn more once you master the fundamentals.

Ask yourself:

  • What question am I trying to find the answer to?
  • Do you see any obvious problems?
  • Who provided the information/how did they know the information?
  • Who created the source you're using/how does this affect the information the source provides?

I'll go into each of these briefly to get you started.

  • What question am I trying to find the answer to?

Remember, you have to know what question you're trying to answer to evaluate the evidence. Who cares how well-packed a box is if it doesn't contain what you ordered. Knowing what question you are trying to answer is how you can evaluate evidence (it's not evidence if it doesn't relate to your question).

Another important aspect is realizing you will have to reevaluate a source for a different question. You will have to reevaluate information if you use it for a different question. The "question" is what helps you determine if information is evidence and if or how you should use it. Without knowing the question, you basically have a sealed shipping box, and it doesn't matter what's in it or even if you open it.

You need to know what question you are trying to answer and when the question changes, you will reevaluate.

  • Do you see any obvious problems?

Evidence evaluation always involves common sense. Asking if you see obvious problems is using common sense. We could ask more questions for evidence evaluation, but they can be overwhelming when you're getting started. If you see potential issues or actual problems with a source or information, you need to make note of it. This item is included so you don't solely answer the other questions and skip anything else that pops into your mind.

  • Who provided the information/how did they know the information?

A primary consideration in evidence evaluation is who provided the information and how they knew it. Often we can't determine this. You should still think about who possibly provided the information and how likely they would have known the information they provided. 

I often hear genealogists ask if they should use a family or local history from the 19th century because it doesn't list any sources. You shouldn't skip using a source. You should evaluate it, and for local and family histories, this question is key.

Who provided the information for the unsourced local or family history? The author probably did not provide all of it; he may have only compiled it. First, you don't have to have formal cited sources to know the source of information. Remember, we care about evidence, not "sources," so some evidence may have a source when other evidence doesn't.

Histories may state where some information comes from. Sometimes they say a resident provided information. They may say a letter was provided by a family member. You have to read the text, more than just the "facts" you are trying to grab, to find these gems. Then you are allowed to use your genealogical imagination.

You don't want to go crazy with potential "who provided this source" options but try to imagine who could have provided the information. Do you think someone just made it up? Remember, use common sense. 

When was the book published? Only someone old enough, but alive, could have provided information (often if a letter or family manuscript from a deceased person is used, it will be mentioned, even if there are few details provided. Our ancestors liked to know information about 200 years earlier came from someone who lived then or knew the people mentioned). 

Look for clues to who provided the information. Sketches in local histories are usually written by the person the sketch is about or possibly their child. A random person doesn't care about writing about a neighbor or a distant cousin. Even if a distant cousin compiles a family history, they have to gather the information from people who know the information ("research" was much harder in the past, especially before the availability of photocopying).

Evaluating 19th-century histories is great practice. They often contain tons of clues you can use for evidence evaluation and "imagining" who provided the information.

Let's flip this question to a census record. 

Usually, we don't know who provided the information. This is where your genealogical imagination needs to combine common sense with knowledge of how records get created. 

For the family or local history, if someone in the family couldn't provide information, the information just wasn't included in the history. 

The census was supposed to include every household. Yes, sometimes people were missed (or intentionally avoided being included), but the enumerator tried to include everyone in his district. That means he'd try and get the information from anyone he could, if necessary. 

The history would have excluded the information if the family wasn't available, but an enumerator would ask one of the children, a neighbor, anyone passing that would provide information. It makes it very hard to know how the person providing the information knew the information. 

The "evaluation" of information like this, where it's very questionable how the informant knew the information, leads to knowing you need to do more to verify the information you find (you still don't want to toss a source, census information that is wrong sometimes becomes a clue.)

As one last example, what about a marriage return (especially pre-20th century records)? 

Once again, you need to combine genealogical imagination with how records are created. Was the record you're looking at present at the marriage? In some times and places, it was. The records I mainly use for marriages most likely were not. 

For a civil marriage return, the return you use almost surely is a copy unless the marriage was performed by a civil officiant that worked in the office where the records were kept (this will once again vary by time and place). 

For my research, which is mainly 19th century southeast U.S., people were often married by a minister (the clerk's copy wasn't present) or a Justice of the Peace. It is possible the J.P. married them at the courthouse and filled in the clerk's return then and there. Or they were married at the bride's home, or the J.P.'s home, or the cousin's house, some neighbor's house, etc. 

Some marriage returns are very specific and tell you this, but many aren't. In my research, the information was provided by the officiant that performed the marriage. Hopefully, he wrote the details down when he performed the marriage and brought it to the clerk to be recorded. 

Sometimes you can tell an officiant came in and reported a whole bunch of marriages after the fact. There are multiple entries in a row where they are all performed by one person, and the dates are out of order from the other marriages recorded. You'll have to decide how or if this affects your research and the specific question you're trying to answer.

  • Who created the source you're using/how does this affect the information the source provides?

Let's look at the marriage return example again. This can be hard to properly explain without an example.

The officiant likely provided the information. Then the court clerk (or whoever's job it was) created the actual return. But is that the source you're using? In part. 

Are you using an abstracted book of marriage records? The abstractor created the book you're using. They could have copied information wrong. The clerk created the original, and he could have also copied information wrong if he was not the actual informant. Those are potential places for error. You have to decide if the information you're finding seems to be affected by these possible issues.

What if you're using a digital image or microfilm of the book of returns (created by the clerk)? In essence, you are using the original. However, use common sense. Is there something wrong with the image you're looking at? Is it blurry? Is part of the page cut off? These are factors that may affect the information.

I haven't listed the next point separately because hopefully, this came up under "do you see any obvious problems." The microfilm (and therefore the digital image made from it) may be hard to read because the records were old.

Microfilm was black and white, so information might be blacked out around the edges where the paper darkened over time. Don't forget that digital images online usually have a place to adjust the brightness, and you may be able to read the text in these dark areas. Microfilm readers also have this option, but it doesn't work as well, and sometimes you can't print a legible copy even if you can read something on a screen.

You should note if you're having trouble reading information because of any type of damage to the record. This is part of evidence evaluation.


If you'd like to learn more, check out the Source Evaluation Workbook.

This workbook takes the evaluation criteria explained in this post and further breaks everything down, making it easier to remember and use. You'll also get printable worksheets to help you practice and a one-page printable "cheat sheet" that lists all the criteria, so you have them handy every time you research.


Bringing it together

The more people and time between you and the information, the more chance for issues. Evidence evaluation is all about judging how this affects the evidence you find, starting by knowing what is evidence (what is your question, information that is relevant is evidence).

Remember to use common sense and remember this is "evaluation." It isn't "evidence calculation." The process is not perfect. You won't always know things about a source that you want to know. You judge how likely it is that information is affected by a potential issue, not calculating the correctness based on issues you're sure occurred.

Getting good at evidence evaluation takes practice, lots of practice. You should be evaluating potential sources from the moment you think of them. Don't avoid using a source because it's not the best, but don't just take every piece of information at face value, either.

If you want more help learning the questions to ask yourself, plus some worksheets to help you practice source evaluation, check out the newest item in The Brick Wall Solution line, the Source Evaluation Workbook.

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