# Why Nonviolent Communication?

To improve communication quality by valuing everyone’s needs. Judgments and violence are tragic expressions of unmet needs.

# What NVC is not

• NOT about being nice.
• NOT about making them to do what we want. It’s about mutual understanding.

# Ways to enhance connection & understanding:

1. vulnerably express our feelings & needs
   • conciousness of the ongoing feelings & needs
   • vulnerability of exposing feelings & needs
2. empathically listen to the feelings & needs ofthe other.
   • Qualities of empathic listening: presence, focus, space, caring, verbal reflection of feelings & needs
   • NOT advising, fixing, consoling, story-telling, sympathizing, analyzing, explaining, …
   • No matter what is said, hear only feelings, needs, observations & requests

e.g. Are you feeling … because you need …?

# Ways to alienate us from one another

• Diagnoses, judgments, labels, analysis, criticism, comparisons, etc.
• Deserve thinking (i.e. that certain behaviors merit punishment or rewards)
  • Demands (denial of other person’s choice; intention to punish those who don’t do it)
  • Denial of choice or responsibility (had to, should, supposed to, they made me do it, etc.)

• CAC: Customer Acquisition Cost is the cost to convert a customer to buy a product/service.
• LTV: Lifetime Value is the estimated net profit we can make from a customer.
• PBP: Payback Period in capital budgeting refers to the period of time required to recoup the funds expended in an investment, or to reach the break-even point. An ideal PBP is about 1 year.

# LTV:CAC Ratio

LTV:CAC Ratio helps you determine how much you should be spending to acquire a customer, so that you can achieve sustainable growth.

1. 1:1 = lose money the more you sell
2. 3:1 or better = good.
3. 5:1 or higher = under-investing in marketing

A skip-list is essentially a linked list that allows you to binary search on it. The way it accomplishes this is by adding extra nodes that will enable you to ‘skip’ sections of the linked-list. Given a random coin toss to create the extra nodes, the skip list should have O(logn) searches, inserts and deletes.

Usecases

• LevelDB MemTable
• Redis SortedSet
• Lucene inverted index

A Bloom filter is a data structure used to detect whether an element is in a set in a time and space efficient way.

False positive matches are possible, but false negatives are not – in other words, a query returns either “possibly in set” or “definitely not in set”. Elements can be added to the set, but not removed (though this can be addressed with a “counting” bloom filter); the more elements that are added to the set, the larger the probability of false positives.

Usecases

• Cassandra uses Bloom filters to determine whether an SSTable has data for a particular row.
• An HBase Bloom Filter is an efficient mechanism to test whether a StoreFile contains a specific row or row-col cell.
• A website’s anti-fraud system can use bloom filters to reject banned users effectively.
• The Google Chrome web browser used to use a Bloom filter to identify malicious URLs.