1 00:00:00,000 --> 00:00:04,338 [MUSIC] 2 00:00:04,338 --> 00:00:08,690 Okay, so in this module we've talked about simple linear regression. 3 00:00:08,690 --> 00:00:12,100 And what we've seen is we've described what the model is. 4 00:00:12,100 --> 00:00:16,620 We just have a single input, single output, and fitting a line or model. 5 00:00:16,620 --> 00:00:21,810 It's just a simple line, to describe the relationship between our input x and 6 00:00:21,810 --> 00:00:23,320 our output y. 7 00:00:23,320 --> 00:00:28,780 We've talked about goodness of fit of a specific line to our data and the measure 8 00:00:28,780 --> 00:00:32,450 being the residual sum of squares that we've talked about in this module. 9 00:00:32,450 --> 00:00:36,360 And we've also talked about some ways to think about 10 00:00:36,360 --> 00:00:40,420 interpreting our fitted line and using it to form predictions. 11 00:00:40,420 --> 00:00:44,820 But a big emphasis was on thinking about how do we actually fit 12 00:00:44,820 --> 00:00:50,070 that line to the data, and we talked about different optimization techniques. 13 00:00:50,070 --> 00:00:55,630 The big one being, gradient descent, and using that to minimize our residual 14 00:00:55,630 --> 00:01:00,720 sum squares, to come up with our fitted line that we're gonna use for predictions. 15 00:01:00,720 --> 00:01:03,450 Even though this is a very very simple and 16 00:01:03,450 --> 00:01:07,350 basic tool, it's actually incredibly powerful. 17 00:01:07,350 --> 00:01:11,046 And we'll look at this in some of our assignments. 18 00:01:11,046 --> 00:01:16,369 [MUSIC]