The use of "match the pairs" exercises is flawed.
(If any contributors are reading this, I hope they don't take it as a put-down on their efforts. I really appreciate that Arabic from English was added to Duolingo. I started using the day I received the email saying that it was available. I use it every day and find it very interesting. That is why I am so disappointed by this feature, which seems to dominate the course.)
I just had a set of exercises with 5 "match the pairs" exercises and nothing else. I got 15 points for that (with the bonus points) and I could have just randomly clicked until each set of pairs was matched. That is not an accurate measure of learning or even "engagement".
I can almost see the value of one "match the pairs" exercise at the beginning of each set of exercises, but multiple exercises does not add any value.
Edit: I just finished 4 sets of exercises with 5, 8, 6, and 7 match the pairs exercises and nothing else. This gave me 60 points to satisfy my "insane" coach setting of 50 points per day. I really prefer the exercises where I can type a sentence. It improves my learning an incalculable amount more than "match the pairs". I have to remember what the words are (house, door, big, amazing, etc.) and I have to learn where the keys are on the keyboard. Those exercises were very frustrating when I had to look at the visual onscreen keyboard to figure out how to type each letter (especially with the way the letters change shape in Arabic), but once I learned most of the "home row" plus and a few more, I was able to do those exercises without the visual keyboard at all.
Edit 2 (response to eastwest_liou) Since the exercises that I had overlapped, I ended up with only about 10 unique pairs overall. I would rather have the multiple choice "which character makes this sound?" type exercise for each of those pairs and then additional sentence questions. The multiple choice can be answered incorrectly, so it reflects in your score. They can also be answered with the keyboard.
Edit 3 Now (10/17/19) I am getting 15 points per lesson and 5 combo bonus points. So, for a lesson with 7 "match the pairs" I received 20 points. I don't know if this is an A/B testing thing, but that is far too many points for such a short and brainless lesson. (This seems to be a display bug. It shows 15+5 points per lesson, but after three lessons I still only had 45 points and needed 5 more for my coach.)
Good point. It's possible to choose or give a wrong answer for the other question types. I am sure Duolingo has thought about it though. What would be a solution then? A maximum amount of tries? A timer? Amount of XP based on amounts of errors (this is true for the stories, where if you have one wrong pairing, you don't get the +2 XP).
Well, those solutions aren't ideal either. So I guess Duolingo is relying on the student to be honest ;)