# Tootsie Roll Pop: How many licks?

Principal Investigator: George Waksman
Data Contributors: George Waksman, Rachel Dillon, Megan Cohen, Jared Coffman, Brad Shilling, Cassidy Verlie

## Abstract

Since the invention of the Tootsie Roll Pop, many men (and women and owls) have asked the question, "How many licks does it take to get to the center of a Tootsie Roll Pop?" Previous research seems to suggest that one can reach the center with three licks and a bite (ref: Mr. Owl), but this does not sufficiently answer the question. Ongoing research is being conducted, and preliminary results have been obtained, towards solving the problem.

## Purpose

The purpose of the research that is being conducted is to systematically determine how many licks it takes to get to the center of a Tootsie Roll Pop.

## Method

### Materials

• 1 Tootsie Roll Pop
• 1 Person

### Setup

1. Unwrap the Tootsie Roll Pop

### Procedure

1. Lick [1] side [2] of the Tootsie Roll Pop
2. Rotate to other side of Tootsie Roll Pop
3. Repeat from Step 1 until center is reached [3]
4. Record results
 [1] A lick is when your tongue is run across the Tootsie Rolls Pop; sucking is strictly prohibitted in this experiment. The tongue need not, necessarily, be retracted into the mouth between individual licks, though it has been found to be more pleasant for the experimenter with frequent tongue retraction.
 [2] Tootsie Roll Pops are shaped in a roughly saucer shape; the broader parts are being referred to as sides.
 [3] The center is determined to have been reached when licking yields the texture of Tootsie Roll, flavor of Tootsie Roll and the discoloration of Tootsie Roll is visible with reference to the candy portion. This eliminates false positives as a result of bubbles in the candy, oddly textured regions and seeing chocolate through candy.

## Data

Trial # Contributor Trial Date Color # Of Licks Trial Duration
1 George Waksman 2004-05-21 Blue 474
2 George Waksman 2004-05-22 Red 522
3 George Waksman 2004-05-23 Dark Red 233
4 George Waksman 2004-05-24 Orange 590
5 George Waksman 2004-05-24 Purple 765
6 George Waksman 2004-05-24 Brown 799 14m
7 George Waksman 2004-05-24 Dark Red 585 9m
8 George Waksman 2004-05-25 Blue 539 11m
9 George Waksman 2004-05-29 Dark Red 610
10 Rachel Dillon 2004-05-29 Blue 601
11 George Waksman 2004-05-29 Dark Red 595
12 George Waksman 2006-07-10 Red 141
13 George Waksman 2006-07-10 Orange 544
14 George Waksman 2006-07-12 Blue 392
15 George Waksman 2006-07-13 Dark Red 378
16 George Waksman 2006-07-16 Green 414
17 George Waksman 2006-07-18 Dark Red 378 12m
18 Megan Cohen 2006-07-18 Brown 607
19 Jared Coffman 1988-06-13 Dark Red 272
20 George Waksman 2006-11-07 Orange 480 12m
21 Brad Shilling 2008-05-05 Dark Red 689
22 Cassidy Verlie 2009-04-14 Pink 572

## Calculations

### Minimum Licks

Since the obtained data represents the licking of both sides, the minimum number of licks for a given Tootsie Roll Pop is half (round up) the number of licks obtained in the trial

### Mean

$$x_0 = \frac{1}{N} \sum_{i = 1}^N x_i$$
double sided: $$x_0 = 508$$
single sided: $$x_0 = 254$$

### Standard Deviation

$$\sigma = \sqrt{\frac{1}{N} \sum_{i = 1}^N (x_i - x_0)^2}$$
double sided: $$\sigma = 164$$
single sided: $$\sigma = 82$$

### Tabulated

Trial # Total Licks Minimum Licks
1 474 237
2 522 261
3 233 117
4 590 295
5 765 383
6 799 400
7 585 293
8 539 270
9 610 305
10 601 301
11 595 298
12 141 71
13 544 272
14 392 196
15 378 189
16 414 207
17 378 189
18 607 304
19 272 136
20 480 240
21 689 345
22 572 286
Mean 508 254
Std. Dev. 164 82

## Conclusions

The data suggests that it takes approximately 508 licks to reach the center of a Tootsie Roll Pop when alternating the licking side. Since the procedure calls for equal licking of both sides of the Tootsie Roll Pop and completion is determined by core contact on either side, one could reach the core with fewer licks by focusing on only one side of the Tootsie Roll Pop. If one were to select the side closer to the core, it would theoretically require approximately 254 licks to reach the center.

The data also suggests a substantial variability in the number of licks required to reach the center, with a standard deviation of 164 licks for two sided licking and 82 for single side licking.

## Error Sources

The small number of trials makes for a very large standard deviation. The standard deviation is so large, in fact, that it is not reasonable to assume the conclusions are accurate.

## Further Research

More trials must be conducted to obtain more data points.

As other possible areas of research, one could look into the effects of tongue size, saliva production, tongue retraction and other variables on the number of licks necessary. The methods contained are easily adapted to further experimentation.

## Outside Data Contributors

Outside data contributions are accepted and greatly appreciated as long as the outlined procedure is strictly adhered to. Contributions may be made by sending details to waksman@gwax.com. Please include number of licks, trial date, lollipop color and contributors full name as incomplete contributions can not be used (trial duration is optional). Please do not contribute poisoned data.