A collaborative (win-win or integrative) negotiation aims to achieve outcomes that benefit both parties while preserving or strengthening the relationship. The focus is on shared objectives, trust, transparency, and long-term value creation rather than short-term gains. Splitting the difference is a compromise-based approach and does not necessarily create joint value. Adversarial or one-sided outcomes are associated with distributive negotiation styles and often damage morale and relationships. CIPS clearly positions collaborative negotiation as the preferred approach where ongoing relationships and mutual benefit are important.
Reference: CIPS L4M5 Commercial Negotiation (CORE), 2nd edition - LO 1.1: Collaborative and integrative negotiation outcomes.

Reference: CIPS L4M5 Study Guide, Section 2.2 - Cost and Price Analysis

In 1983, Peter Kraljic devised a means to segment the supplier base in the article in HBR. In this, he argued that supply items should be mapped against two key dimensions: risk and profitability.
Risk relates to the likelihood for an unexpected event in the supply chains to disrupt operations. For instance, in important areas of spend, such as tire suppliers for an automotive are business critical, and should a disruption occur, the auto company is likely itself to face substantial problems.
Profitability describes the impact of a supply item upon the bottom line. For certain areas of spend, such as stationery, supplies have only a negligible effect on profits. In other categories, a single source of supply can make or break a business.
Putting these two dimensions together yields a classic two-by-two matrix.
Source: Peter Kraljic, HBR
Reference:
- CIPS study guide page 63-73
- What Is The Kraljic Matrix? (forbes.com)
LO 1, AC 1.4

Good negotiators are attuned to all stimuli and not just the verbal and written information exchanged. Tone of voice, body language, facial expressions and other clues from TOP are noticed, and with experience and knowledge, interpreted correctly. This interpretation may also involve knowledge of culture norms and values. A smile, a 'yes' and the type of hospitality received, (in the business context), can mean very different things in different international business cultures.
Trained negotiators will consider non-verbal communication (such as nodding and smiling) and body language as one source of signal from TOP, but will rarely rely wholly on this as a guide to what TOP is thinking or feeling. Furthermore, international and regional cultural considerations must be included here to avoid errors in interpretation. Emotional intelligence also has an important role in forming a more holistic perspective of what TOP may be thinking or feeling.

While compromise seems fair, it often erodes credibility and weakens long-term negotiation outcomes.
Skilled negotiators avoid "splitting the difference" automatically, since it signals weak preparation and can encourage exploitation in future talks. Instead, agreements should be built on objective value, data, and tradeables. Compromise has a place, but reliance on it damages strategic positioning. CIPS stresses integrative or principled negotiation over simplistic middle-ground settlements.
Reference: CIPS L4M5 (2nd ed.), LO 1.1 - Dangers of compromise and importance of principled negotiation.