export type KanoResponse = 'like' | 'expect' | 'neutral' | 'tolerate' | 'dislike';
export type KanoCategory = 'must_be' | 'one_dimensional' | 'attractive' | 'indifferent' | 'reverse' | 'questionable';
/**
 * Standard Kano evaluation table.
 * Rows: functional answer, Columns: dysfunctional answer.
 *
 *              like      expect    neutral   tolerate  dislike
 * like         Q         A         A         A         O
 * expect       R         I         I         I         M
 * neutral      R         I         I         I         M
 * tolerate     R         I         I         I         M
 * dislike      R         R         R         R         Q
 */
export declare const KANO_TABLE: Record<KanoResponse, Record<KanoResponse, KanoCategory>>;
/** Categories that qualify a feature to advance past the Kano step. */
export declare const ADVANCING_CATEGORIES: KanoCategory[];
/**
 * Classify a feature into a Kano category using the standard evaluation table.
 * @param functional  The respondent's answer to "How would you feel if this feature were present?"
 * @param dysfunctional The respondent's answer to "How would you feel if this feature were absent?"
 * @returns The Kano category for this feature based on the respondent's answers.
 */
export declare function classifyKano(functional: KanoResponse, dysfunctional: KanoResponse): KanoCategory;
/**
 * Filter classified items, retaining only those with advancing categories
 * (must_be, one_dimensional, attractive).
 * @param classifications A map of item value → KanoCategory
 * @returns An array of item values whose category is an advancing category.
 */
export declare function filterKanoSurvivors(classifications: Map<string, KanoCategory>): string[];
/**
 * Determine the next step in the funneled survey based on how many items survived Kano filtering.
 * - >= 4 survivors → proceed to MaxDiff
 * - exactly 3 survivors → skip MaxDiff, go directly to Pairwise
 * - < 3 survivors → survey ends after Kano
 * @param survivorCount The number of items that passed Kano filtering.
 */
export declare function determineNextStep(survivorCount: number): 'maxdiff' | 'pairwise' | 'end';