Learn more about analytics and research best practices, as well as real world examples and solutions for nonprofits.

RECENT POSTS

Jan 29, 2019

Are My Response Rates Statistically Significant?

I’m taking a different approach in today’s blog to discuss a problem I continue to run into when I am working with clients. And that is testing whether the response rates in a direct mail test are meaningful.

Now response rates are relatively uncomplicated to test. Anyone can do it. That’s because there are only two possible outcomes: Response or nonresponse.

Here’s an online testing tool for you to use.

After you click on the link, you will need to enter your data. The “base sizes” are the number of pieces mailed in each of your tests. The “proportions” are the number of responses for each test divided by the number of mailed. You can choose your confidence level (we recommend 90%), and then click calculate.

Voila!

I suggest using a 90% confidence level because it is a high standard. That means if you have this difference in 100 tests, in 90 of those tests the difference will be real. The “Results” box will state either “Significant” or “NOT Significant.” You don’t need to understand statistics to use this tool!

Another helpful metric to know is your average gift size. Now, testing average gift size is more work to calculate, because the values you are testing can range from $0.01 to $1 million or more. That means you can’t use summary statistics (averages) to calculate significance. Instead, you need the entire gift distribution. Plus, you will need a more robust software tool than Excel to do this. We use SPSS.

We suggest that you talk with your analytics people to have them help you through testing average gift size differences.

Thank you for joining me for today’s stats class.

Fundraising Forward

Postage rates and problematic delivery are making me rethink how fundraising might need to adapt moving forward. In 2024, First Class postage is a whopping 73 cents (who knew when those “forever” stamps don’t put the amount on them?) and nonprofit postage is between...

read more

Test First Class Postage this Fall

One of the disturbing USPS trends – other than raising the cost of postage every year – is the bulk delivery of appeal letters with nonprofit postage. Over the past year, when I check my mailbox for the appeal letters I’m seeded on, I have noticed that I receive all...

read more

Top 5 Mistakes: #1 Stopping New Donor Acquisition

I have been analyzing the fundraising business for nearly three decades and over the years I keep seeing nonprofit organizations making the same mistakes. These errors hold organizations back. If you are new to fundraising, please commit yourself to avoiding these...

read more

ARCHIVES

© 2024 Analytical Ones