Starting 2022-07-12 Experiment (#18083)

This involves declaring the 20220603-variant-a the winner of the past
experiment; note in the past experiment there was not a statistically
significant winner.

This new experiment adds a variant that deviates from the new
incumbentby way of reintroducing the follows an author and adjusting the
tag follow weights.

Closes forem/forem#18082

```shell
$ diff config/feed-variants/20220617-variant-a.json \
  config/feed-variants/20220712-variant.json
```

Results in:

```shell
3c3
<   "description": "Blend of 20220603-variant-b and 20220603-variant-a",
---
>   "description": "Builds from 20220617-variant-a (see https://github.com/forem/forem/issues/18082)",
50a51,57
>     "following_author": {
>       "cases": [
>         [0, 0.8],
>         [1, 1]
>       ],
>       "fallback": 0.8
>     },
70,73c77,80
<         [0, 0.5],
<         [1, 0.85],
<         [2, 0.9],
<         [3, 0.95],
---
>         [0, 0.3],
>         [1, 0.9],
>         [2, 0.95],
>         [3, 0.98],
```

config/feed-variants/20220712-variant.json

@@ -0,0 +1,104 @@
+{
+  "max_days_since_published": 15,
+  "description": "Builds from 20220617-variant-a (see https://github.com/forem/forem/issues/18082)",
+  "order_by": "final_order_by_random_weighted_to_score",
+  "reseed_randomizer_on_each_request": false,
+  "levers": {
+    "daily_decay": {
+      "cases": [
+        [0, 1],
+        [1, 0.99],
+        [2, 0.985],
+        [3, 0.98],
+        [4, 0.975],
+        [5, 0.97],
+        [6, 0.965],
+        [7, 0.96],
+        [8, 0.955],
+        [9, 0.95],
+        [10, 0.945],
+        [11, 0.94],
+        [12, 0.935],
+        [13, 0.93],
+        [14, 0.925]
+      ],
+      "fallback": 0.9
+    },
+    "comments_count_by_those_followed": {
+      "cases": [
+        [0, 0.95],
+        [1, 0.98],
+        [2, 0.99]
+      ],
+      "fallback": 0.93
+    },
+    "comments_count": {
+      "cases": [
+        [0, 0.8],
+        [1, 0.82],
+        [2, 0.84],
+        [3, 0.86],
+        [4, 0.88],
+        [5, 0.9],
+        [6, 0.92],
+        [7, 0.94],
+        [8, 0.96],
+        [9, 0.98]
+      ],
+      "fallback": 1
+    },
+    "featured_article": { "cases": [[1, 1]], "fallback": 0.85 },
+    "following_author": {
+      "cases": [
+        [0, 0.8],
+        [1, 1]
+      ],
+      "fallback": 0.8
+    },
+    "latest_comment": {
+      "cases": [
+        [0, 1],
+        [1, 0.9988]
+      ],
+      "fallback": 0.988
+    },
+    "matching_negative_tags_intersection_count": {
+      "cases": [
+        [0, 1],
+        [1, 0.5],
+        [2, 0.4],
+        [3, 0.3],
+        [4, 0.2]
+      ],
+      "fallback": 0
+    },
+    "matching_positive_tags_intersection_count": {
+      "cases": [
+        [0, 0.3],
+        [1, 0.9],
+        [2, 0.95],
+        [3, 0.98],
+        [4, 1]
+      ],
+      "fallback": 1
+    },
+    "privileged_user_reaction": {
+      "cases": [
+        [-1, 0.2],
+        [1, 1]
+      ],
+      "fallback": 0.95,
+      "negative_reaction_threshold": -10,
+      "positive_reaction_threshold": 10
+    },
+    "public_reactions": {
+      "cases": [
+        [0, 0.9988],
+        [1, 0.9988],
+        [2, 0.9988],
+        [3, 0.9988]
+      ],
+      "fallback": 1
+    }
+  }
+}

config/field_test.yml

@@ -28,10 +28,36 @@
 ################################################################################
 experiments:
   # NOTE: Our feed strategy testing experiment must begin with "feed_strategy"
+  feed_strategy_starting_20220712:
+    # NOTE: Required as we want only want to consider for conversion events that
+    #       occurred on or after the given start_date.
+    started_at: 2022-07-12
+    variants:
+      - 20220617-variant-a
+      - 20220712-variant
+    weights:
+      - 50
+      - 50
+    goals:
+      - user_creates_pageview
+      - user_creates_article_reaction
+      - user_creates_comment
+      - user_publishes_post
+      - user_views_pages_on_at_least_four_different_days_within_a_week
+      - user_creates_article_reaction_on_four_different_days_within_a_week
+      - user_creates_comment_on_at_least_four_different_days_within_a_week
+      - user_publishes_post_on_four_different_days_within_a_week
+      - user_views_pages_on_at_least_four_different_hours_within_a_day
+      - user_views_pages_on_at_least_twelve_different_hours_within_five_days
+      - user_views_pages_on_at_least_nine_different_days_within_two_weeks
+      - user_publishes_post_at_least_two_times_within_week
+      - user_publishes_post_at_least_two_times_within_two_weeks
   feed_strategy_starting_20220617:
     # NOTE: Required as we want only want to consider for conversion events that
     #       occurred on or after the given start_date.
     started_at: 2022-06-17
+    ended_at: 2022-07-12
+    winner: 20220617-variant-a
     variants:
       - 20220617-variant-a
       - 20220617-variant-b