# Normalization Rules

Use this reference when you need to compare vegetables or grocery baskets fairly across platforms.

## Unit Normalization

Always normalize vegetables and fresh groceries by a meaningful unit:
- leafy greens: per 250g or 500g when listings vary a lot
- root vegetables: per 500g or 1kg
- tomatoes, cucumbers, peppers: per 500g or by clear pack weight
- eggs: per piece and per 10 or 12 pack
- meat: per 500g or per kg, and note chilled vs frozen when relevant

If two listings are not the same weight, do not compare sticker price directly.

## Packaging Adjustment

Check whether the item is:
- loose selection
- pre-packed
- trimmed or cut
- premium selected grade
- bundled with other items

If one item is cleaner, larger, or more premium, say the comparison is directional rather than exact.

## Basket Math

For basket comparisons, include:
- sum of item prices
- coupon-adjusted total
- threshold required to unlock savings
- extra filler items needed
- delivery fee
- packaging fee
- pickup inconvenience if applicable

A basket is not truly cheaper if:
- it only wins after buying items the user does not need
- it forces an inconvenient second step such as distant pickup
- the savings are wiped out by fees or time cost

## Freshness Adjustment

Cheaper is not always better if:
- leafy vegetables appear older or smaller
- fruit and fragile produce have weaker quality confidence
- the low price comes from leftover or mixed-grade inventory

Use wording like:
- `低价成立，但可能便宜在规格和鲜度。`
- `这更像价格优先，不像品质优先。`
- `如果你更在意做出来的口感，这个低价不一定真值。`

## Delivery Versus Pickup

Normalize these as part of cost:
- home delivery fee
- packaging fee
- ETA reliability
- pickup distance or inconvenience

If the user is cooking soon, treat long pickup or unstable ETA as a real cost.

## City Variance

Never present a city-specific grocery answer as national truth.

If only partial location data is available, say:
- `这个比较更像你当前城市的方向性判断`
- `换城市后，仓和价签可能明显不同`
- `如果你给我城市和购物清单，我可以把判断压得更准`