If using fresh strawberries, wash them, and hull them.
Mash the strawberries a layer at a time in something like a pie plate using something like a potato masher.
You should end up with around 1 litre (4 cups / 32 oz) of mashed strawberries. A tidge under or over is fine.
Put in a large stainless steel pot.
Add the water.
Add the pectin and stir till the pectin is dissolved.
Put on a burner.
If using SUGAR or SPLENDA: Bring to a full rolling boil over the heat and when it reaches that point, start timing 1 minute. Add in sugar or Splenda, bring back to a boil that you can't stir down, and boil for 1 minute after that point. Remove from heat.
If using STEVIA: Bring to a full rolling boil over the heat and when it reaches that point, start timing 1 minute. Remove from heat. Add stevia to taste.
Should it start to gel before this time is up, remove from heat, you're done.
Remove from heat.
Skim off any foam, if there is any.
Ladle into 125 ml (4 oz) or quarter-litre (½ US pint / 8 oz) jars.
Leave 1 cm (¼ inch) headspace.
Debubble, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jars for 10 minutes; increase time as needed for your altitude.