My Journey

Baby Shower Predictions: A Statistical Analysis

At our recent baby shower, guests participated in predicting a variety of factors regarding the baby-to-be, as well as the labor and delivery process. As a lover of research and statistical analysis, I thought it would be fun to compile the prediction data and report on the results.

Even with a call for additional predictions via Facebook and Twitter mediums, please note that the sample size is small – nor is it a random sample – and, as a result, does not yield great statistical power.

All participants (n = 20) were aware of the ultrasound technician’s sex determination (female), as well as the expected due date (August 20th). Participants predicted the following variables:

  • Sex
  • Date of Birth
  • Time of Birth
  • Weight
  • Length
  • Hair Color
  • Eye Color
  • Time in Labor

Summary Statistics

All participants did not dispute the ultrasound technician’s determination and predicted the baby would be female. No participant predicted the baby would be born on the expected due date of August 20th. Birthdates ranged from August 10th to August 27th, with August 22nd and August 25th being the most popular dates with 3 guesses each.

Regarding time of birth, a majority of participants predicted the baby would be born in the morning, with the earliest prediction at 3am. The afternoon and evening predictions ranged from times of 3:23pm to 11:30pm.

On average, participants predicted the baby would weigh 7.22 pounds (minimum = 6, maximum =8.4) and measure 19.95 inches in length (minimum = 16, maximum = 23.5). Regarding hair color and eye color predictions, a plurality of participants guessed the baby would be brunette and have blue eyes.

The average amount of time participants predict I will spend in labor is 19.16 hours, though these responses ranged from 2 hours to 5 days. This variation is likely due to differing interpretations regarding the item: some participants may have interpreted this to mean the time in active labor, while others may have perceived it to represent the total time from first contraction.

Some Fun Research Questions

Q1: Were responses from men significantly different than those from women?

Though very few men participated in this survey, there are still some interesting differences, especially due to the more clustered predictions from the male sample. Females predicted a longer labor (21.5 hours) as compared to males (5.67 hours), t(17) = 2.08, p<0.05. As stated previously regarding the potential for differing interpretations of this variable, it is possible this comparison is also impacted by the limitation in the clarity of the item. Females predicted a heavier baby (7.4 pounds) than males (6.4 pounds), t(4) = 4.69, p<0.05. However, females and males did not differ in their predictions regarding the length (19.8 inches and 20.8 inches, respectively) of the baby, t(2) = -0.73, p>0.05.

All male participants predicted the baby would arrive after the due date; 67% predicted the baby would be bald, and 67% predicted blue eyes.

Q2: Did time in labor predictions vary significantly between parents and non-parents?

Parents did predict a longer labor (31.7 hours) than non-parents (12.4 hours), however this was not a statistically significant difference, t(7) = -1.2, p>0.05 primarily due to the large variance within each group. Again, the general differences between the groups could be due to differing interpretations regarding what was meant by time in labor. It is quite possible that some participants interpreted the item to include the time from the first contraction, while others interpreted the item to represent only active labor.

There were no differences in weight prediction based on parental status, t(16) = -0.36, p>0.05. Parents (7.3 lbs) and non-parents (7.2 lbs) guessed nearly identical weights for the baby-to-be, though non-parents showed slightly greater variation in predictions with a minimum of 6 pounds to a maximum of 8.4 pounds. On the other hand, predictions from parents ranged from 6.5625 pounds to 8.125 pounds. Parents predicted a longer baby (20.3 inches) as compared to non-parents (19.8 inches), though the difference was not statistically significant, t(14) = -0.63, p>0.05.

All parent participants predicted the baby would arrive after the due date.

Q3: Were family predictions significantly different than friend predictions?

Family members predicted a longer labor (32.8 hours) than friends (8 hours), though the statistical significance of this difference is in question due to the interpretation of the variable itself, t(8) = -1.89, p<0.05. Family and friends did not differ in their predictions regarding the weight of the baby, t(18) = 1.00, p>0.05, with predictions at 7.1 pounds and 7.3 pounds, respectively. Friends predicted the baby would be smaller in length (19.2 inches) as compared to the predictions made by family members (20.9 inches), t(15) = -2.41, p<0.05.

With the exception of one participant, all family members predicted the baby would arrive after the due date.

Q4: Who was better at predicting the outcome in each pairing: Men vs. women, parents vs. non-parents, family vs. friends?

Pending birth results!

I’ll follow up on this post after the birth with all of the true values of the variables, as well as some analysis to address Question 4, so be sure to stay tuned come August and September!

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