There are a couple of tools in After Effects to determine how the motion of any element will be.

One such tool is the Anchor Point: a sort of axis that, depending on its location, will represent the starting point from which an object will transform. Again, it seems irrelevant, but when you start animating, you will realize the importance of setting the Anchor Point to correctly scale or rotate an animated text or even a shape in your compositions.

Scaling a text while in motion

To understand how the Anchor Point determines where an element transforms from, create a New composition and type a word using the Text tool. Then, activate it from the Toolbar or by clicking Ctrl + T or Cmd + T. 

Once you have your text ready, activate the Selection tool and notice that there is a peephole in addition to the eight dots around your word. That's the Anchor Point.

Now that you recognize it: 

1. Go to the Timeline and expand the Text layer properties tab.
   
2. Open the Transform option.

3. Go to Scale and reduce the size of your text by changing the first blue highlighted value next to this property.

4. Now that your text is minor set the Time Indicator at the beginning of the Timeline. Then, turn on the stopwatch next to the Scale option.

5. Move the Time Indicator forward a couple of seconds and change the blue highlighted value next to Scale until you make your text larger.

6. Select the two keyframes that formed on the Timeline as if you were going to group them and press F9.

7. Place the Time Indicator at the beginning of the Timeline and hit the space bar to play your animation.

Did you notice how when you scaled down your text, it got more minor from the Anchor Point location? If this element is entirely centered, you didn't see it, but if the Anchor Point is in some corner, it acted as an axis that pulled your word from that location. That's what we'll modify.

How to set the Anchor Point to change the starting point of a text transformation

You may not always want the starting point to enlarge a text when you apply motion to it to be its center. However, and considering the previous steps, if you want your word to scale progressively from its middle, you can set the Anchor Point to change the starting point of a text transformation: 

1. Go to the Toolbar and activate the Anchor Point feature. It is to the left of the Rectangle Tool.

2. Once you have turned on that button, go back to your composition and manually move the Anchor Point to the center of the text you typed.

3. Play your animation again by pressing the space bar on your keyboard to see how the motion changes.

Tip: Activate the anchor point whenever you want to modify the starting point from a text you want to animate is transformed, and remember it should not always be located in the center, as it depends on your goal.

Try moving the Anchor Point to other positions to see the differences in the animation.