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Who are You More Alike?

Mannequin lined up next to a ruler
Jump to [materials] [investigation strategies] [scaling] [data analysis] [conclusions]

By Rebecca Kranz
– a high school freshman intern at the Museum of Science when she created this investigation

When a baby is born, affectionate onlookers will often comment on the features of the baby.  “It has its mother’s eyes” or “it has its father’s nose” are phrases commonly used to describe the baby’s face.  Now there is a legitimate way to see exactly who you take after, your mom or your dad, and in what regard. 

Materials you need

    Pictures of people, with ruler for reference. To start you need a picture of those whose faces you plan to measure, ideally with a ruler in the picture to make it easy to calibrate measurements.  If possible take the pictures yourself.  This will ensure that the picture provides good measurements, as well as allow you to create an accurate scale. 

    Software. You’ll need to get yourself acquainted with AnalyzingDigitalImages, as these are the tools you will be using to make your measurements. AnalyzingDigitalImages is available as part of the DEW software bundle.

    Alternative to software: a ruler. If you do not have access to these tools, it is also possible to make measurements on the actual picture using a ruler.

Investigation strategies

In the photograph on the right, the line is measuring the length of the bottom part of the nose. When using the AnalyzingDigitalImages software, the length of the line,  in pixels, is shown, as well as information regarding the intensities of colors along the line. There are many other facial features you can measure. Be creative.  Come up with as many measurements as you can.  The more measurements you make, the more numbers you have to analyze and the more accurate your conclusion will be.

Scaling the Image when Using a Ruler

Same mannequin lined up against a ruler in greyscale

In the gray part of the printed photograph above, four inches along the ruler was measured as five inches.  Using proportions you can scale all of the measurements accurately.   In this case, the 4 inches on the picture correspond to the 5 inches shown by the ruler.  As a proportion this is 4/5, which equals 0.8.  This means that for every measurement you make, simply divide by .8 to get the actual length of the line. If you are using the digital photograph with the AnalyzingDigitalImages software, this scaling occurs automatically for all length and area measurements.

Data Analysis Strategies

The saved measurements from AnalyzingDigitalImages are easily imported into EXCEL or other spreadsheet programs.  The coordinates of the lines you drew, the lengths of the lines, the average intensities of them are available in the spreadsheet. You will need to move columns of data next to the other sets of data to make graphing easier.  If you used the hard copy, the scaled measurements and the labels must be manually entered into EXCEL in the same fashion.   

In order to create a graph, the sets of data must be in adjacent columns. 

Mom’s Data

Dad’s Data

My Data

Length of Face

11.6

9.29

9.09

Highlight the data you would like to include, click on the chart wizard, and follow the steps to making a graph in EXCEL.   Do not add the unit of measure to the number (11.6 inches). Just insert the number itself and add units to the axis labels.  In order to have each point on the graph labeled, make sure to highlight the column with the name of the measurements along with the data.

Drawing Conclusions

So, who are you more alike?  Can you find certain patterns in the graph?  Are there some ways you are like each parent?  Which measurements helped you to come up with your decision?  Are there more measurements you could have made on your face or other faces?   Could you expand the investigation to include other family members?  Try it out.  Construct your own investigation on facial similarities.  Expand your investigation to include more than your family.  Let your imagination go wild.

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